1. Urine and faeces, and two-hour bile samples from adult male rats dosed with [14C]diphenylmethane were analysed for benzhydrol and 2- and 4-hydroxydiphenyl-methane by silica gel GF t.l.c. and 14C-determination. 2. Mean values of 48.4% and 17.7% of the administered 14C were present in 24 h urine and faeces, respectively. Benzhydrol and 2- and 4-hydroxydiphenylmethane comprised 3.7%, 0.3% and 4.8% respectively of the 14C isolated from urine and 3.1%, 0.8%, and 4.8% respectively of the 14C isolated from faeces. 3. Bile samples (2h) contained 3.2% of the administered radioactivity. After treatment with beta-glucuronidase/aryl sulphatase, 71.9% of the recovered biliary radioactivity was identified as benzhydrol (37.5%) and 4-hydroxydiphenylmethane (34.4%).