Family therapy may help addicts remain drug abstinent by improving family functioning. In a outpatient pilot study eight addict families were evaluated before and after 16 weeks of multiple family therapy (MFT), while the addict was maintained on naltrexone, an opiate antagonist. The Beavers Timberlawn Family Assessment was used to rate videotapes on problem solving, family structure, individual autonomy, and affect. The 8 families showed significant improvement in global functioning, problem solving, structure, and autonomy, but not in affect. One addict relapsed during the 10 month follow up, and his was the only family that functioned worse at follow up. We concluded that MFT can help addict families progress from chaotic interactions to more stable family structures and from rigid to more flexible family functioning. This improvement in family functioning may be associated with ex-addicts remaining abstinent.