Objective: Recent advances in techniques for detecting oral premalignant lesions and oral squamous cell carcinoma have improved the chances of early diagnosis. Adjuncts for detection of lesions include toluidine blue staining and cytologic examination. The primary objective of this study was to assess the efficacy of 1% toluidine blue (modified Mashberg technique) and cytology in detection of oral premalignant lesions and oral squamous cell carcinoma. Method and Materials: The study included 86 participants suspected of having oral premalignant lesions or oral squamous cell carcinoma. One percent toluidine blue was applied to the lesions, followed by cytology. A biopsy was then performed on the tissue. Histopathologically proven oral premalignant lesions/oral squamous cell carcinoma lesions were analyzed for sensitivity, specificity, postive predictive value, and negative predictive value of both screening techniques. The association of screening techniques and histopathologic diagnosis among the oral premalignant lesions, oral squamous cell carcinoma, and benign groups were analyzed using the Fisher exact test. P .05 was considered significant. Results: The specificity and sensitivity for oral squamous cell carcinoma and oral premalignant lesions detection of 1% toluidine blue was 81.35% and 66.67%, respectively, while cytology attained 77.97% and 70.37%, respectively. Negative predictive value and positive predictive value were 84.21% and 62.06% for 1% toluidine blue and 85.18% and 59.37% for cytologic examination, respectively. Comparison of 1% toluidine blue and cytology with histopathologic diagnosis shows a significant difference between carcinoma/epithelial dysplasia and no dysplasia and carcinoma/epithelial dysplasia and benign lesions (all, P .05). Conclusion: The results of this study suggest that 1% toluidine blue and cytology have high sensitivity, specificity, and accuracy in detecting oral premalignant lesions and oral squamous cell carcinoma and can be used as an adjunct for early detection of such lesions. Keywords: cytology, oral cancer, premalignant, screening, toluidine blue