Summary Leukocytic infiltrates are a morphologic feature of most solid tumors, including uterine cervical intraepithelial neoplasia (CIN) and invasive carcinoma. We have studied 50 cases of CIN I, CIN II, CIN III, invasive carcinoma and normal controls in order to evaluate the inflammatory response. Two markers - CD68, a macrophagespecific marker, and ICAM-l, present on leukocytes, blood vessels and epithelial cells - were employed. Results have demonstrated similar inflammatory cell counts in normal, CIN II and CIN III lesions by both markers, and lower counts for CIN I. Invasive carcinomas demonstrated a statistically significant increase in infiltrate density by both CD68 (p<0.002) and ICAM1 (p<0.05). Macrophage density by either marker did not correlate with Human Papillomavirus (HPV) presence, specific type, or evidence of co-infection with several types. We conclude that the inflammatory response to cervical intraepithelial neoplasia is inadequate. The elevated cell counts in invasive carcinomas may reflect a reaction towards invasion rather than tumor-specific immune response. Depression of inflammation in CIN I lesions may be associated with active viral replication in these lesions.