Patterned hair loss which includes both male pattern hair loss (MPHL) or androgenic alopecia (AGA) and female pattern hair loss (FPHL) is the most common indication for hair transplant surgery. However, not all such patients are candidates for hair transplants. There are eight conditions that cause patients to not be appropriate candidates. These are: diffuse unpatterned alopecia (DUPA), cicatricial alopecia (CA), patients with unstable hair loss, patients with insufficient hair loss, very young patients, patients with unrealistic expectations, patients with psychologic disorders such as body dysmorphic disorder (BDD) and trichotillomania, and patients who are medically unfit. In addition, there are patients who are poor candidates and who should undergo hair transplantation only if they understand and accept limited results. The key to identifying these patients involves performing careful and detailed history and examination at the time of consultation.