Plasma fatty acid profiles from maintenance hemodialysis patients (n = 9) were compared with those from healthy volunteers (n = 9). Hemodialysis patients had significantly higher levels of oleic acid, 15.3 +/- 1.1 vs. 8.9 +/- 0.6% (p less than 0.0001), and lower levels of arachidonic acid (6.0 +/- 0.5 vs. 8.4 +/- 0.3%, p less than 0.0009). Linolenic and linoleic acids, the essential fatty acid and precursors of arachidonic acid, were also significantly lower than normal in the dialysis group. These data show that dialysis patients have fatty acid abnormalities suggesting relative depletion of essential fatty acids. These observations are important because these abnormalities may play an important role in the pathogenesis of some common clinical conditions associated with uremia, such as a constellation of skin problems, fragility of erythrocytes, lipid anomalies and hormonal aberrations.