Mark A. DiAntonio

Mark A. DiAntonioFor more than 25 years, Mark’s civil litigation and employment law practice has focused on the defense of businesses in the healthcare, construction and manufacturing sectors. At the beginning of his legal career, Mark served as Staff Counsel for Allegheny Health, Education & Research Foundation in Philadelphia. He then joined a civil litigation law firm where he eventually became a partner, defending doctors and hospitals against medical malpractice claims, while also representing businesses in employment law disputes and providing advice on employment policies and compliance issues.

Mark then became the managing attorney of the litigation department at a law firm in Florida, where he tried cases and supervised associates working on civil litigation and employment law matters at the law firm’s three offices. He defended businesses and employers against personal injury, property damage, breach of contract, discrimination, and wage & hour claims. Mark also directed and performed a variety of workplace investigations, including fatal accidents and worker disputes, and counseled employers on contract language and regulatory compliance issues.

In 2009, this native Philadelphian returned home and continued practicing law at a law firm prominent in the medical malpractice defense bar. Upon the retirement of the named partners at that law firm, Mark transitioned his law practice to Kilcoyne & Nesbitt, LLC in October 2021. Mark defends claims involving medical malpractice and general liability matters, and represents businesses in contract disputes. Mark also assists buyers and sellers in business sales/acquisitions, and advises businesses regarding succession planning and relationship terminations or “business divorces.”

Before becoming a lawyer, Mark served in the U.S. Army as an enlisted soldier in a field artillery unit, and later became a lieutenant in a combat engineer battalion. Mark also worked as the Business Editor for the Intelligencer Journal in Lancaster, PA before changing career paths to pursue a career in the law.


  • Penn State University – B.A. Journalism
  • University of Pittsburgh School of Law – J.D.


  • Pennsylvania
  • Maryland
  • Florida
  • United States District Court for the Eastern District of Pennsylvania, Southern District of Florida, and Maryland
  • United States Court of Appeals for the Third Circuit
  • United States Supreme Court


Contact Us