Objectives: The aim of the study was to evaluate the diagnostic efficacy of colposcopy and to determine the strength of correlation between colposcopic impression using the Reid Colposcopic Index (RCI) and histopathology. Material and methods: This was a prospective cross-sectional study carried out at the colposcopy clinic of Bakırköy Dr Sadi Konuk Education and Research Hospital, Department of Obstetrics and Gynecology, between June 2011 and September 2011. A total of 105 women who met the selection criteria were included in the study. All women underwent colposcopy and the final diagnosis was made using RCI. Colposcopy-guided biopsy was obtained from the abnormal areas. In cases when colposcopy did not reveal any lesion, a four-quadrant biopsy from the squamocolumnar junction was taken, which served as the gold standard. Results: According to the Reid scoring system, there were 60% of benign cases, whereas 27.6%, 5.7%, and 6.7% of the women were diagnosed with CIN 1, CIN 2, CIN 3, respectively. As far as histologic results were concerned, 62.9% of the subjects were benign, whereas 25.7%, 3.8%, and 7.6% of the patients were diagnosed with CIN 1, CIN 2, CIN 3, respectively. The correlation between the Reid scoring system and histologic results was statistically significant (p>0.05). Conclusions: The correlation between colposcopic lesions graded with RCI and histology was strong, particularly in women who had HGSIL on a Pap smear. Good correlation between colposcopic imaging using RCI and histopathology makes it a reproducible technique, easy to implement in colposcopy clinics.