Prior literature suggests that length of stay (LOS) on medical inpatient units is increased by the coexistence of depression and physical illness. The present study examined 532 psychiatric inpatient admissions to determine if physical illness increased LOS for patients grouped by diagnostic categories of psychosis, depression, personality disorder, anxiety disorder, adjustment disorder, bipolar disorder (not depressed), and other psychiatric disorders. LOS for depressed patients was significantly longer for those with any physical final diagnosis (mean = 20.08 days) than for depressed patients with no physical diagnosis (mean = 11.48 days). LOS was also longer for all patients with physical diagnoses (mean = 19.31 days) than all patients with no physical diagnosis (mean = 13.13 days). No other specific diagnostic group (psychosis, personality disorder, and so forth) showed significant differences in LOS for any associated physical illness vs no physical illness. The study results tend to indicate that physical illness is associated with increased LOS for depressed psychiatric patients but not for other specific diagnostic groups. Depressed patients may 1) mask physical illness by depression-generated physical complaints; 2) prioritize mood symptoms over physical symptoms; and/or 3) may suffer from feelings of hopelessness or be pessimistic that their physical symptoms will be effectively treated and, therefore, not report their physical symptoms.