The crude ethanol extract of leaves of Sonneratia caseolaris Linn. (Sonneratiaceae) was screened for its antinociceptive and antidiarrhoeal activities. The extract produced significant writhing inhibition in acetic acid induced writhing in mice at dose of 250 and 500 mg/kg body weight (P<0.01) comparable to the standard drug diclofenac sodium at the dose of 25 mg/kg of body weight. When tested for its antidiarrhoeal effects on castor oil induced diarrhea in mice, it increased mean latent period and decreased the frequency of defecation significantly at the dose of 500 mg/kg body weight (P < 0.05) comparable to the standard drug loperamide at the dose of 50 mg/kg of body weight. The overall results tend to suggest the antinociceptive and antidiarrhoeal activities of the extract.