Seborrheic keratoses (SK) are common, benign, pigmented epidermal tumors. Collision tumors with seborrheic keratosis has been reported only in a few studies which include both benign and malignant tumors. Malignant change arising within seborrheic keratoses is rare. Here we are presenting a series of five cases of collision tumors arising in association with seborrheic keratosis. These include seborrheic keratosis with keratoacanthoma, bowen’s disease, dermal nevus and malignant melanoma.