Ninety three cases of tonsillitis were studied for antistreptolysin O titre and C-reactive protein before and 2 months after tonsillectomy. Marked reduction is seen in the level of antistreptolysin after tonsillectomy. Before operation the levels ranged between 1: 1360 and 1: 170. After operation they ranged between 1: 480-1: 120. Cases with strong positive C-reactive protein turned weak positive while those with weak positive reaction either remained weak positive or turned negative