Iris crystals in three patients with idiopathic iridocyclitis, Fuchs' heterochromic iridocyclitis, and iridocyclitis associated with systemic pseudolymphoma are described. Two patients had iris crystals in one eye, and the other patient had bilateral involvement. The number of iris crystals in each eye ranged from one to multiple crystals. Iris crystals were minute and refractile and glistened with light; they have previously been reported to be Russell bodies and to be associated with hypergammaglobulinaemia. However, two of the patients, who underwent serum protein electrophoresis, did not demonstrate hypergammaglobulinaemia.