Intracerebroventricular (ICV) infusion of basic fibroblast growth factor (FGF-2) at 50 ng/h for 5 days in male BALB/c mice suppressed the daily intakes of water and food (n = 4). Intakes were reduced on the second day, and were suppressed until the second day after stopping the infusion. The same infusion for 4 days had little effect on the high intakes of 0.3 M NaCl solution and water induced by prolonged ICV infusion of angiotensin II, or the daily food intake in these experiments (n = 7). However, the same infusion for 3-4 days reduced the increased intake of NaCl solution in Na-depleted mice (n = 8), reduced the increased water intake of water-restricted mice (n = 6 or n = 7), and reduced daily food intake in both experiments. Ventricular enlargement was noted in mice at the end of these experiments but, for reasons advanced, did not appear to account for the responses. The results indicate that FGF-2 may have an inhibitory role in these ingestive behaviours.