This study was designed to determine the individual fatty-acid pattern in plasma and in two adipose tissue sites of rats submitted to portacaval shunt (PCS) using the button technique. The animals were studied both in a fed state and after a 48-hour fast. Glucose, ketone bodies (KB), lactate and pyruvate levels were also measured. The results of the shunted animals were compared with pair-fed and freely fed control groups. In PCS rats, plasma free fatty-acid (FFA) levels were not significantly higher than in freely fed controls. beta-Hydroxybutyrate was significantly lower in PCS rats compared with both control groups. A 48-hour fast caused an elevation of plasma FFA and KB in all groups, but in PCS rats this increase was less pronounced. Lactate levels did not decrease during fasting in PCS rats, as they did in the control groups. PCS did not modify plasma FFA or the adipose tissue composition, neither in fed nor in fasted rats. We conclude that the PCS rats operated upon by using the button technique show mild modifications in lipid metabolism, affecting the fatty-acid composition neither in plasma FFA nor in adipose tissue.