Methanolic extract of the simple ascidian, Phallusia nigra Sav. was subjected to anaesthetic activity by intracutaneous wheal method. The extract, when administered at a dose of 10% and 15% caused highly significant anaesthetic activity when compared to the standard drug xylocaine (1%). The mean sleeping time and percentage relaxtion of muscle was also highly significant in the extract treated groups compared to the standard drug, Aminobarbitone
