The accurate identification of cells as either malignant or benign reactive mesothelial cells is a diagnostic problem in conventional smear cytology. The lower sensitivity is due to bland morphological features of cells, loss of cellular material and changes due to different laboratory methods. Data regarding clinical, laboratory and radiological findings of all cases sent to laboratory were collected.Fresh serous fluid sample received were physically examined by noting color, appearance, presence of clot and mucin. Out of the 54 cases of pleural fluid, by conventional smear cytology 43 cases (80%) were benign (Inflammatory), five cases (9%) were suspicious for malignancy & six cases (11%) were positive for malignancy. By cellblock preparation, 41 cases (76%) were benign (inflammatory), 13 cases (24%) were positive for malignancy. In the present study of pleural fluid samples from 54 cases (Table 38), by conventional smear cytology benign effusions were noted in 43 cases (80%), malignant effusions in six (11%) cases & five cases (9%) were suspicious for malignancy. By cellblock preparation 41 cases (76%) were benign (inflammatory) & 13 cases (24%) were malignant.In the present study of peritoneal fluid samples from 51 cases (Table 40), by conventional smear cytology benign effusions were noted in 39 cases (76.5%), suspicious in 9 cases (17.6%) & malignancy in 3 cases (6%). By cellblock preparation 39 cases (76.5%) were benign, 12 cases (23.5%) were malignant.