This study is a prospective, observational study done for two years, comprising of 267 cases. Their episodes were while tapping pleural cavity, peritoneal cavity and pericardial sac, pleural, ascitic and pericardial fluids were collected. Majority of the samples received were from our hospital (98%) while 2% (5 samples) were obtained from outside. The male cases (55%) outnumbered the females (45%). And, a maximum number of instances in quinquagenarian among males and sexagenarian among females. In peritoneal fluids, females (29/30) outnumbered males. Fifty-nine (22%) samples showed the presence of clot with the majority being in pleural fluid (35/59). Few of the cases of TB showed neutrophilic (10%) or eosinophilic (2.5%) exudate instead of lymphocytic effusion. In contrast, a few cases of liver cirrhosis showed exudative effusion instead of transudative because of bacterial peritonitis. Majority cases were exudates (58.2%) excluding the peritoneal fluids, out of 71 cases of known malignancy. Out of these, 50% of the malignant effusions were nonhemorrhagic. Common microorganisms were gram-negative bacilli and grampositive cocci. There were three unusual cases in this study, viz: Eosinophilic effusion, Parasite (Ascaris) in pleural fluid and an example of a second malignancy. If the effusion is suspected for malignancy, the fluid typing of exudate or transudate may be done. Also, wet mount preparation for abnormal cells may be done before Examination of fixed smears for cancerous cells, as we did not find any transudate fluid positive for malignancy. Diagnostic effusion tapping, followed by immediate processing of fluid in a laboratory may improve cytological outcome. Malignant effusions may not be hemorrhagic in appearance. Rarely effusion may be the first manifestation of malignancy.