BACKGROUND Cytological assessment using various morphological parameters helps segregate breast lesions in fine-needle aspiration cytology (FNAC) into different categories. The prognosis and the line of management of each category differ accordingly. OBJECTIVE This study aims at assessing the validity of Modified Masood's Scoring Index (MMSI) by the evaluation of cytomorphological features of various breast lesions compared with histopathological findings. METHODS This is a cross-sectional study done in 65 female patients with palpable or nonpalpable breast lesions, undergoing FNAC and biopsy over a period of 18 months from December 1, 2012, to May 31, 2014. METHODS MMSI categorizes breast lesions, based on six cytological parameters into different categories such as nonproliferative breast disease (NPBD), proliferative breast disease (PBD) without atypia, PBD with atypia, and malignancy. The findings are compared with gold standard histopathological diagnosis. METHODS Percentage of agreement, Kappa statistics, and Chi-square test. RESULTS Of the total 65 cases, all cases in MMSI category I and IV showed good histopathological correlation. The agreement between MMSI and histopathology was 93.8% which is more when compared with 72.3% agreement between cytology without scoring and histopathology. MMSI has increased the diagnostic accuracy of FNAC to 93.8% from 80%. CONCLUSIONS The scoring system is easily reproducible, simple, and reliable. MMSI proved good histopathological correlation in category I and IV. This scoring technique has clearly demarcated those cases requiring surgical management. It is applicable for palpable and nonpalpable cases.