Our Story

Cislo & Thomas LLP’s story begins in 1970 when Donald M. Cislo, a patent attorney from Chicago, Illinois, decided to venture west. Having earned his chemical engineering degree from ITT, and going to DePaul University College of Law at night, Don decided that intellectual property would be extremely important in Southern California. Passing up a great opportunity at Hughes Aircraft, Don liked his prospects better at a small patent firm in Santa Monica, even if it meant less money.

Chuck Thomas also studied electrical engineering in Illinois and, in fact, attended DePaul Law School several years after Don. They formed their two-attorney partnership in 1979, and have faithfully served the Southland’s inventors and small businesses as California has grown into an innovative powerhouse.

Dan Cislo grew up with a special fondness for science, reading Scientific American when other kids were reading the sports pages. He went to UCLA and graduated with a degree in Systems Engineering – a combination of electrical and mechanical engineering with computer science. Like his Dad, he went on to study law at night while engineering by day. With a strong background in engineering, and a law degree from Loyola Law School, he went to work for a prominent downtown intellectual property law firm.

Dan also started his own company, SecureCase Co., around the same time, developing and manufacturing patented locking cases for firearms, still used by the military, FBI and law enforcement agencies throughout the world. In 1986, Don wanted to grow the Cislo & Thomas practice, and made Dan an offer he could not refuse. Dan became the managing partner in 1996 and has never looked back, loving the wonders of science, the possibilities of technology, and the excitement of business.

The firm has grown, technology has changed, and the speed of business has increased. Yet, the firm continues to focus on an integrated approach to protecting, licensing, and litigating patent, copyright, trademark, and trade secret matters. Few firms can match Cislo & Thomas’ Quality Client Care® (QCC®) approach, which requires IP specialists who know engineering and science as well as litigation and business strategies. The firm is not only AV rated by Martindale-Hubble (the highest rating that can be received), but also listed in the Bar Register of Preeminent Lawyers, which places the firm in the top 5% of law firms nationwide.

With offices in West Los Angeles/Santa Monica, Westlake Village, Santa Barbara, Pasadena, and San Diego, California, the firm’s patent attorneys serve the greater Southern California area, including Los Angeles, Ventura, and Orange Counties. We work in all aspects of patent, trademark, copyright, trade secret and domain name law. Our lawyers have the technical training and experience to handle any IP matter, and excel in searching, clearing, filing, licensing, maintaining, and litigating intellectual property matters. Our local offices provide a convenient venue to meet our attorneys and discuss how we can best help you protect your intellectual property.