Nail-patella syndrome (NPS) is an autosomal dominant genetic defect, which may be associated with, or closely linked to, the locus controlling palmar and plantar hyperhidrosis (HH). A clinical review of a family with NPS involving six generations was performed. Data were accumulated by personal examination and analysis of medical and family records for the traits characterizing NPS as well as the coincidence of HH. A family pedigree of each entity was constructed and the pedigree for HH was compared to the NPS pedigree. Thirty-three of sixty-eight members of the extended family were affected with NPS and nine members had HH. The NPS pedigree supported the previously known autosomal dominant mode of inheritance. The incidence of HH indicated a direct inheritance and occurred only in members affected with NPS. The pedigree provides evidence for concluding that HH occurred as a spontaneous mutation transmitted as an autosomal dominant trait closely linked to NPS or that HH represents a previous unrecognized associated disorder.