Cutaneous adverse drug reactions (ADR) are skin conditions due to a drug, regardless of the way of administration. Knowledge about their frequency, clinical manifestations and histopathological patterns is essential for prevention and early diagnosis, avoiding complications and reducing morbidity. This work assessed the incidence of cutaneous ADR in skin biopsies from patients with inflammatory dermatoses, and determined their histopathological patterns. Skin biopsies from patients with inflammatory dermatoses, obtained in the years 2006-2007 at the Pathology Division of the HU/UFJF, were analyzed. The different histopathological patterns were grouped, the cases were statistically analyzed and a clinicopathological matching was attempted. Of the 1409 skin biopsies, 304 cases of inflammatory dermatoses were diagnosed,31 corresponding to cutaneous ADR. The most frequent histopathological pattern was vacuolar interface dermatitis (41.9%). The most frequently involved drug was captopril. Identification of histopathological patterns and anatomoclinical correlation are indispensable for the differential between cutaneous ADR and the other inflammatory dermatoses, allowing for an early and precise diagnosis and reducing treatment and hospitalization costs.