Background: Serous cavity effusions comprise a large number of cytology specimens in every cytopathology setup. Cavity effusion specimens play a crucial role in patients clinical management. The guidelines and categories for reporting serous effusioncytology (IACGRSE) was introduced by The Indian Academy of Cytologists (IAC)in 2020. Thus aim of the study was to introduce uniform system of reporting serous effusion in cytopathology of ourdepartment and to analyse interobserver variability among participants using IACGRSE 2020 categories along with category wise agreement. Material and methodology: A cross-sectional prospective study was carried out over a period of 2 months. The samples of serous cavity were routinely processed and reporting was done according toIACRSE 2020 by two investigators. Kappa statistics were used to assess the diagnostic utility, feasibility and interobserver variability. Results: Age ranged between10 years to 92 years with themean age of 54.14 ± 20.331 of the participants. There were 34 (64%) males in the present study. Maximum cases were Ascitic fluid 28 (56%). Observer 1 analysed 60% cases as Category II and observer 2 analysed 68% cases as category II. Kappa statistics showed a substantial significant agreement between 2 observers with Kappa value of 0.675% and 67.5% agreement. (p value-0.000). Conclusion: Interobserver agreement showed a Substantial agreement among the observers. IACGRSE 2020 categories can be used for reporting and interpretations of serous lesions.