Mann & Mairone was formed in 1987 in Chicago, Illinois USA as a firm specializing in US federal taxation, international commercial and tax, and securities (private placement). In 1994 the firm opened its office in Israel and in 2004 opened additional offices in Luxembourg and Hong Kong.

The firm has expanded its areas of practice to include counterterrorism law, human rights law, general commercial, private international law, estate planning, intellectual property, employee benefits and real estate. Members and affiliates of the firm are fluent in English, French, Hebrew and Arabic.

In 2002, Mann & Mairone formed the Counterterrorism Research Group (CRG), a unique research division dedicated to operational research in Arabic, Farsi, English, French, German, Spanish and Portuguese, tracing international money laundering activities and financing terrorist organizations. The firm has commenced complex civil litigation on behalf of over 1600 victims of terrorism against international financial institutions engaged in such money laundering.