In an open study, thirty-five patients with active rheumatoid arthritis were treated with phenytoin. Various clinical and laboratory parameters showed good improvement after phenytoin. Early morning stiffness was significantly reduced after 8 weeks (p less than 0.05); pain index (p less than 0.001), articular index (p less than 0.01) and grip strength (p less than 0.01) showed significant improvement after 24 weeks. There was significant reduction in erythrocyte sedimentation rate (p less than 0.01). Except for three patients (skin rash in one and gastric irritation in two), all others tolerated phenytoin well. The results of the present study support the usefulness of phenytoin as a disease-modifying drug for rheumatoid arthritis.