OBJECTIVES: Actinic keratoses are characterized by dysplastic epidermal lesions that occur in pale-skinned individuals chronically exposed to intense sunlight. It is one of the most commonly treated skin conditions but its prevalence in the Brazilian population is still unknown. The objective of this research is to describe the profile of the patients diagnosed with AK in São Paulo city. METHODS: A two months health survey was performed in the city of São Paulo in which 10 dermatologists registered the profile of the patients diagnosed with actinic keratosis.  RESULTS: The dermatologists saw 4961 patients in two months, 5,4% (269 patients), were diagnosed with AK (58% women). The mean age of the patients was 65 years old. 42% informed a family history of AK and 21% history of nonmelanoma skin cancer. Among the patients 80% of the participants belonged to the two initial categories of the Fitzpatrick Scale. 39% of the lesions were hyperkeratotic and the most common localizations of the lesions were face (35%) and the upper extremity (26%). Seventy-one percent of the patients were treated with surgical destruction of the lesions (chemical cautery, cryotherapy, electrocautery) and just 29% were prescribed to administer topical therapy (5-fluourouracil, imiquimod, retinoic acid). CONCLUSIONS: The prevalence of actinic keratosis in this sample is 5,42%. The most affected sites were face and upper extremity of these elderly patients with very fair skin. The preferred treatment was physical destruction of the lesions instead of noninvasive topical therapy.