ABSTRACT Oral squamous cell carcinoma (OSCC) is the most common cause of morbidity and mortality in India. Buccal mucosa is the most common site because of tobacco quid. Several parameters for the assessment of OSCC have been studied like lymph node metastasis, tumor stage, grade, and perineural invasion. Tumor-associated tissue eosinophilia is another parameter, on which several studies have been done because of its favorable and unfavorable prognosis. The aim of our study is to study quantitative and qualitative eosinophilia in premalignant and malignant lesions of squamous origin in oral cavity with respect to tumor-associated blood eosinophilia. A retrospective study was done at Tertiary care hospital between January 2016 and December 2016. A total of 150 cases of premalignant (oral leukoplakia and dysplasia) and malignant oral squamous cell carcinoma (of various grades) along with blood pictures were evaluated.