An outbreak of trichinosis caused by ingestion of horse meat occurred in December 1993 in France; more than 500 people were affected. We compared the immediate and midterm efficacy and tolerability of thiabendazole and albendazole as therapy for the 46 patients seen in our department. Forty-four patients (96%) were treated. The first 26 patients received thiabendazole therapy; the next 18 received albendazole therapy. All the patients were tested with prednisone. Eight relapses occurred (seven in the thiabendazole group and one in the albendazole group [not significant]). Side effects of treatment were reported by seven patients, all of whom were treated with thiabendazole (P = .01). Six months after treatment, 16 of the 31 patients who responded to a questionnaire still had symptoms, the most frequent of which were myalgias (81%) and fatigue (69%). No significant difference was observed between the two treatment groups. The immediate efficacy of thiabendazole and albendazole as therapy for trichinosis was comparable, but albendazole was better tolerated.