KEYWORDS ABSTRACTFine needle aspiration cytology; Intraabdominal lesions; Modified Ultrafast Papanicolaou Stain; Papanicolaou Stain; Quality Index Scan to discover online Background & Objective: Modified Ultra-fast Papanicolaou (MUFP) stain has been developed from Papanicolaou stain (PAP) with the goal to improve staining quality, minimize staining time for obtaining immediate cytological diagnosis and to check specimen adequacy during Ultrasound guided Fine needle Aspiration Cytology (US guided FNAC). The aim of this research was to study the cytomorphological features of intra-abdominal lesions with help of US guided FNAC and to assess the diagnostic utility of Modified Ultrafast Papanicolaou stain in cytological diagnosis. Methods:This cross-sectional study enrolled consecutive 100 subjects in N.K.P Salve Institute of Medical Sciences and Research Centre, Nagpur, which is a tertiary teaching hospital in India, from July 2015 to June 2017 who underwent US guided FNAC for Intra-abdominal lesions. Fine needle aspiration was done under ultrasound guidance and the smears were divided into two groups. Wet smears were fixed in 95% ethyl alcohol for conventional PAP staining and air dried for MUFP. After staining, results were evaluated on basis of the cytological features. Scores were given according to four parameters namely background of smears, staining pattern, cell morphology and nuclear staining. Quality index was calculated from the ratio of score achieved to the possible maximum score. Results:The most common organs involved were ovaries (46 %) followed by liver (11%) and most common lesions were malignant (68 %). The cytological characteristic showed significant difference in all four parameters (P<0.05) when MUFP stain smears were compared with PAP stain smears. There was also statistically significant difference when cumulative score and Quality Index were compared (P<0.001) between the two stains. Conclusion:The US guided Fine needle aspiration (FNA) is simple, safe, rapid and inexpensive technique useful in cytological diagnosis. MUFP stain is fast, reliable and has better diagnostic utility for cytological diagnosis when compared to PAP stain. Main Subjects: Diagnostic Pathology