Objective: To evaluate the role of squash cytology in rapid on-site adequacy checking (ROSAC) of image-guided gun biopsy and to determine its diagnostic accuracy at a tertiary cancer center. Study Design: This was a prospective study on 183 patients undergoing image-guided biopsy. Squash smears were prepared from biopsy cores and checked for adequacy by cytotechnologists. When adequate, more cores were sampled from the same area for histopathology. If inadequate, the procedure was repeated at the same sitting on a different area. The squash smears were reported by cytopathologists within 4 h after staining with conventional Papanicoloau stain. The results were compared with the final histopathology report. Results: The sampling was representative in 95.6% cases with concordance for adequacy in 97.3% cases. The sensitivity, specificity, positive predictive value and negative predictive value of squash cytology for diagnosis of the lesion were 99.4, 92.7, 97.7 and 97.4%, respectively. Conclusions: Squash cytology is an ideal and cost-effective technique for ROSAC of image-guided biopsies, which ensures adequacy, avoids repeat procedures and prevents delay in diagnosis. It can be effectively performed by trained cytotechnologists in radiology clinics. Squash cytology is also a cost-effective tool offering rapid diagnosis which expedites planning of treatment.