Mark I. Wallach - Thacker Robinson Zinz LPA

Mark I. Wallach

Listed in Best Lawyers since 1995
Phone: 216-456-3848


MARK litigates and tries complex business disputes, concentrating on corporate, business tort, utilities and public law litigation.  His in-depth focus includes consultant and accountant liability litigation, contract disputes, Uniform Commercial Code issues, trade secrets and non-competition covenants.  Mark also works with clients to resolve zoning  and other issues involving local and state governments.

Mark regularly appears in state and federal courts in Ohio and throughout the country on behalf of both plaintiffs and defendants.  His recent experience includes:



  • Winning one of the largest business-case jury verdicts in Ohio in a lawsuit for fraud by a developer in relocating a major tenant to an unsuitable site.
  • Obtaining a multi-million dollar settlement for an industrial corporation damaged by the failure of a new enterprise computer system to perform as promised.
  • Recovering more than $30 million for the liquidation estate of a large Ohio insurance company, including $10 million from the company’s auditors, nearly $9 million from its corporate attorneys, and more than $4 million from former officers and directors.
  • Winning the first case in the Ohio Supreme Court establishing the right of Ohio municipalities to charge impact fees to developers to pay for infrastructure necessitated by new development.
  • Establishing, by an Ohio Supreme Court ruling, the proper statute of limitations for claims brought against utilities by customers.
  • Settling a claim by a large public university for millions of dollars, paid by the supplier of faulty computer software to the university.
  • Negotiating multi-million dollar settlements from the former auditors and from former officers and directors of a defunct surety bond company outside of Ohio.

Mark is a member of the Federal Court Panel for ADR Procedures and was previously a member of the Civil Justice Reform Act Advisory Group.  He has been honored consistently with inclusion in The Best Lawyers in America, Who’s Who in America, Leading Lawyers by Cleveland’s Inside Business magazine, and by Chambers USA. Clients told Chambers that he “is a litigator who isn’t afraid to face down the toughest opponent and gets the job done.”

Mark served as chairman of The Sculpture Center, and is currently member of the executive committee of the Cleveland Chapter of the American Constitution Society.  He is a member of the Cleveland Metropolitan and Federal Bar Associations and the Cuyahoga County Law Directors Association, and is a member of the Pro Bono Committee of Northeast Ohio Legal Aid.

From 1974 to 1975 Mark served as a clerk for Chief Judge Frank J. Battisti in U.S. District Court.  He was an associate with Baker & Hostetler from 1975 to 1979 and served as chief trial counsel for the City of Cleveland from 1979 to 1981.  Mark began his tenure with Calfee Halter & Griswold LLP in 1981, becoming a partner in 1983, and joined Thacker Martinsek LPA in 2012.


Of Counsel

Principal Practices

  • General Litigation
  • Business, Corporate and Commercial Litigation
  • Public Law Litigation
  • Business Claims Litigation


  • Harvard Law School, J.D., cum laude, 1974
  • Wesleyan University, B.A., magna cum laude, Phi Beta Kappa, 1971


  • State of Ohio
  • U.S. District Courts (Northern and Southern Districts of Ohio, Eastern and Western Districts of Michigan)
  • U.S. Courts of Appeals for the Federal, Sixth and Eighth Circuits
  • U.S. Supreme Court
Thacker Martinsek LPA
(216) 456-3848


Wesleyan UniversityBA 1971Wesleyan UniversityBA 1971Harvard University Law SchoolJ.D. 1974

Client Comments

"My experience to date has been limited with lawyers thank God. However, lawyers' reputations, coupled with our legal system, does not make the thought of working with both very appealing. I was pleasantly surprised by Mark's approach and found that he viewed my situation as if he were me and would approach the case with high moral character and not view me as only a customer who was paying him for his service. There was no question I would ask that he did not address until I was completely satisfied and had a clear understanding of the question. He was very good at explaining what appeared to be very complicated issues and making them easy to understand. He also approaches each issue with a tenacity and conviction that I have seldom seen in anyone in the legal profession."

-Marc Gottlieb
MHG Sales

"Mark Wallach has represented several of my municipal government clients in very complex litigation matters. Mr. Wallach is a very good attorney with excellent attorney skills. He provides excellent representation to his clients at the trial court level, the appellate court level, and in business transactions. He is professional, timely, thorough, and responsive to client demands."

"Mark does a great job of seeing all the potential issues in complex litigation and developing a strategy for addressing and resolving them. He also has always given me good advice based on what he believes is the best strategy for any issues that arise during litigation. However, if we decide on a course of direction different from the one he recommended, he accepts the decision and pursues that course of action aggressively and with no reservations. I am very pleased with the work Mark has done for us."

-Doug Hertlein
Chief Deputy Liquidator
Ohio Insurance Liquidation Office

Office Location

One Cleveland Center, Suite 2330
1375 East Ninth Street
Cleveland, OH 44114
United States

Practice Areas

Commercial Litigation
Litigation - Land Use and Zoning
Litigation - Municipal