William (Bill) P. Pistorius


Location: Chicago, IL

Phone: 312.606.7835


Bill, a shareholder with Clausen Miller P.C., focuses his practice on complex tort litigation. He frequently defends manufacturers in product liability actions, and construction entities sued following workplace accidents. Bill has handled the defense of numerous premises liability matters, and has defended consumer class action lawsuits in Illinois, New York, and Louisiana. Bill has represented municipalities, police and private security officers, dispatchers, and ambulance companies in civil rights and tort matters.

Bill regularly represents clients following large-scale fire and explosion losses, involving deaths, personal injuries, and property damage. He often begins handling such matters in the immediate aftermath of a loss, retaining appropriate experts to investigate origin, cause, and spread issues. If suit is filed, Bill participates in all aspects of litigation through trial. Representative fire and explosion cases Bill has handled include:

  • Defending a product manufacturer in a lawsuit involving 100 deaths and over 200 personal injuries resulting from a Rhode Island nightclub fire.
  • Obtaining summary judgment in favor of a sprinkler contractor following a fire at an Illinois casino causing over $80 million in damages.
  • Defending a commercial property developer in a lawsuit alleging tens of millions of dollars in property damage resulting from a wildfire on California’s Catalina Island.
  • Defending a product manufacturer after a warehouse fire in Iowa caused tens of millions of dollars in property damages.
  • Defending a commercial tenant following an explosion during the manufacturing process at an Indiana warehouse causing a multi-million dollar loss.

Bill has successfully mediated and tried many cases, and has briefed, argued, and won appeals in the Illinois Appellate Courts, the Illinois Supreme Court, and the United States Court of Appeals for the Seventh Circuit.

Bill joined Clausen Miller in 1994, after serving as an Assistant Illinois Attorney General, and an Assistant Cook County State’s Attorney. He is a graduate of the Teaching Advocacy Skills program of the National Institute for Trial Advocacy. He has an AV Preeminent rating with Martindale-Hubbell indicating the highest ranking in legal ability and ethical standards as determined by his peers in the legal community.


  • J.D. DePaul University College of Law, 1987
  • B.A. University of Illinois, 1984

Bar Admissions

  • Illinois

Court Admissions

  • U.S. District Court, Northern District of Illinois
  • U.S. Court of Appeals, Seventh Circuit


  • American Bar Association
  • Illinois State Bar Association
  • Chicago Bar Association
  • Defense Research Institute


  • Martindale Hubbell AV® rating
  • Leading Lawyers, 2020
  • Chicago

    Illinois 60603

    10 South LaSalle Street

    Chicago, Illinois 60603

    T: 312.855.1010 TF: 800.826.3505 F: 312.606.7777 Office Managing Partner: Dennis D. Fitzpatrick

  • New York

    New York 10005

    28 Liberty Street 39th Floor

    New York, New York 10005

    T: 212.805.3900 TF: 800.826.3505 F: 212.805.3939 Office Managing Partner: Carl M. Perri

  • Mission Viejo

    California 92691

    27285 Las Ramblas

    Suite 200

    Mission Viejo, California 92691

    T: 949.260.3100 TF: 800.826.3505 F: 949.260.3190 Office Managing Partner: Ian R. Feldman

  • Florham Park

    New Jersey 07932

    100 Campus Drive

    Florham Park, New Jersey 07932

    T: 973.410.4130 TF: 800.826.3505 F: 973.410.4169 Office Managing Partner: Carl M. Perri

  • Michigan City

    Indiana 46360

    200 Commerce Square

    Michigan City, Indiana 46360

    T: 219.262.6106 TF: 800.826.3505 F: 312.606.7777 Office Managing Partners: Paige M. Neel, Kimbley A. Kearney

  • Appleton

    Wisconsin 54914

    4650 W. Spencer Street

    Appleton, Wisconsin 54914

    T: 920.560.4658 TF: 800.826.3505 F: 920.968.4650 Office Managing Partner: Patrick L. Breen

  • Stamford

    Connecticut 06902

    68 Southfield Avenue

    2 Stamford Landing Suite 100

    Stamford, Connecticut 06902

    T: 203.921.0303 TF: 800.826.3505 F: 212.805.3939 Office Managing Partner: Matthew J. Van Dusen

  • Tampa

    Florida 33609

    4830 West Kennedy Boulevard, One Urban Center

    Suite 600

    Tampa, Florida 33609

    T: 813.509.2578 TF: 800.826.3505 F: 312.606.7777 Office Managing Partner: Dennis D. Fitzpatrick

  • San Francisco

    California 94111

    100 Pine Street

    Suite 1250

    San Francisco, California 94111

    T: 415.745.3598 TF: 800.826.3505 F: 949.260.3190 Office Managing Partner: Ian R. Feldman