Anterior chamber inflammation was measured in 71 eyes after argon laser trabeculoplasty with the laser flare-cell meter (Kowa FC-1000). Visual acuity, tonometry, and laser flare measurement were performed before and 3, 6, and 18 hours and 2, 4, 7, 14, 30, and 90 days after argon laser trabeculoplasty. Anterior chamber inflammation peaked 2 days after argon laser trabeculoplasty. Forty-nine percent of the eyes showed significant inflammation, with a flare increase of more than 10 photon counts per millisecond over prelaser values. Inflammation was significantly more frequent in pseudoexfoliative glaucoma (69%) and pigmentary glaucoma (100%) than in primary open angle glaucoma (23%). Post-argon laser trabeculoplasty relative pressure decrease was significantly more important in the group of patients with inflammation than in the group without inflammation in the early and late follow-up periods. Topical nonsteroidal anti-inflammatory treatment (diclofenac sodium) was needed in 17 patients, who readily responded to treatment within 72 hours.