Tattooing and permanent make-up have become mainstream procedures. Many factors play a role in the final outcome of a tattoo and the satisfaction of the customer. The technical and artistic skills of the tattooist will determine the esthetic result and will help to guide the customers in their decision and choice of the tattoo. Although tattooing is by many considered as safe one should be are aware of the risks of complications related to this body modification technique. Some customers have a medical problem and some doubt about the safety of the procedure. People with increased risk of adverse events often seek medical advice prior to decide to get a tattoo or PMU. Physicians should not only be informed about the medical history of their patients but also have some basic knowledge of the practice of tattooing and the effects this procedure can exert on the skin and on the health condition of the patient. Contraindications and special precautions with regard to skin diseases and specific systemic conditions will be addressed in this article.