Although chronic fatigue is a common complaint in family practice, little research has focused upon differentiating physical causes from psychological causes based upon historical information. This pilot study was conducted to determine whether psychological and fatigue scales could be used to identify potential causes, and to assess the utility of using fatigue characteristics to distinguish psychological from physical fatigue. Family health center patients were randomly selected and interviewed for the presence of fatigue. Those with significant fatigue were asked to participate in a structured, in-depth interview concerning fatigue characteristics, psychiatric conditions, and symptom checklists. Of 248 patients interviewed, 17 (6.9%) had fatigue. Fourteen patients had at least one psychiatric disorder. Fatigue severity correlated with depression severity in depressed patients (r = 0.83, p < 0.02) and with severity of phobic anxiety (r = 0.55, p < 0.1) in panic attack patients. However, fatigue characteristics generally did not differentiate between those with and without associated psychological disorders.