The trial of 77-year-old Hafiz Khan and 26-year old Izhar Khan began Friday with opening statements.
Both have pleaded not guilty to charges of conspiracy and material support to terrorism.
Each count carries a maximum prison sentence of 15 years.
Assistant U.S. Attorney John Shipley Jr. says the father and son sent more than $50,000 to the Pakistani Taliban.
Defense attorneys for the men argued prosecutors are misinterpreting thousands of phone conversations, as well as intercepts and bugged conversations of an informant.
The trial is expected to last about two months.