1. MIC against 20 strains of staphylococcus isolated from skin infections was studied. MIC was less than or equal to 0.05 mug/ml in 11 strains and greater than 100 mug/ml in 9 strains. 2. Clindamycin-2-phosphate was injected intramuscularly to rats at the dosis of 10 mg/kg in solution of 10 mg/ml. The serum and skin levels of this drug were determined at 0.5, 1, 2, 4 and 7 hours. Mean serum levels of 4 rats were 0.893, 0.578, 0.463, 0.268 and 0.167 mug/ml respectively at 0.5, 1, 2, 4 and 7 hours. The corresponding skin levels were 0.500, 0.707, 0.431, 0.313 and 0.269 mug/g. 3. Clindamycin-2-phosphate was used clinically in 7 patients of skin infection with the following result: excellent in 2 cases, fair in 3 cases and poor in 2 cases. Abdominal pain was complained in one case and loose stool in one case.