Accumulation of cadmium (Cd) was determined in the muscle and gill tissues of Nile tilapia Oreochromis niloticus (L.) exposed to sublethal concentrations of Cd (0.1 and 1.0 mg/L) under laboratory conditions for 15 and 30 days, in the absence or presence of green algae Cladophora glomerata (L.) Kutz. Results showed that muscles, irrespective of treatments, accumulated less Cd than gills. Cd accumulation significantly increased in both the tissues in treatment groups as compared to control groups (p<0.05), except in muscle of fish exposed to 0.1 mg/L Cd for 15 days (p>0.05). Presence of green algae did not influence accumulation of Cd in muscle. But Cd accumulation was significantly reduced in gills, in the presence of green algae, in all treatments groups, except in 0.1 mg/L Cd exposure for 15 days. In the presence of green algae, the reduced Cd accumulation in gills might be due to its uptake from the medium by the algae.