Pigmentary disorders are a common finding in primary care pediatric practice. Tuberous sclerosis and neurofibromatosis type 1 are two pigmentary disorders that have had many changes in their diagnostic and therapeutic approach. This review focuses on the significant advances in the past few years in the genetics and diagnostic criteria of these disorders. A review of the clinical presentation of neurofibromatosis is provided along with the revised diagnostic criteria for tuberous sclerosis. A logical approach to testing the tuberous sclerosis patient and his or her family is included.