With tattoos becoming increasingly mainstream, dermatologists are more and more often consulted by patients who are considering getting an ornamental, cosmetic, or even a medical tattoo, and who subsequently ask for advice. This includes not only patients with chronic skin diseases such as psoriasis or atopic dermatitis but also patients with other medical conditions. This review first explores the reasons why patients may want to get a tattoo and aims to offer some key information to dermatologists on what they should know about tattooing and the main risks associated with this procedure. Second, the risks and recommendations of tattooing in patients with specific skin diseases are described more in detail, and the relative and strict contraindications discussed, including the necessity to discontinue certain treatments that could influence the outcome of the procedure and the final result. Our aim was to provide dermatologists with the current knowledge they need to help their patients make adequate and informed choices on skin art, focusing specifically on considerations in patients with chronic skin conditions. Finally, other aspects regarding some general systemic conditions and concomitant diseases that the patient could present are also addressed. In particular, the risks of tattooing in patients with diabetes, coagulation disorders, heart conditions, immunosuppressive treatments, and pregnancy are discussed.