Various aspects of the safety of moxidectin for goats were tested in six experiments, where two pharmaceutical forms (1% injectable solution and 0.1% oral drench) of the drug were used. In experiments I and II, the drug was administered to adult goats or to kids in the following doses: 300, 600, 900 and 2×300 μg kg −1. In experiments III and IV, the drug was administered to goats before and during pregnancy in the dose of 300 μg kg −1. In experiments V and VI, the drug was administered to goats concurrently with an enterotoxaemia vaccine or with a flukicide in the dose of 300 μg kg −1. An increased ( P<0.05) prevalence of animals with adverse reactions was recorded among adult goats, which received 900 μg kg −1 of moxidectin 1% injectable solution and among kids which received 600 or 900 μg kg −1 of moxidectin 1% injectable solution or 900 μg kg −1 moxidectin 0.1% oral drench. The salient reactions of the animals were: indifference to the environment, drowsiness, somnolence, salivation, ataxia and refusal of kids to suck their dams; they were observed 4–8 h after administration of the drug and regressed within 36 h after it. No other statistically significant adverse reactions were observed among experimental animals; no adverse reproductive effects were recorded; no effects were observed during simultaneous administration of the enterotoxaemia vaccine or the flukicide. It is concluded that although the drug appears to be safe for use to goats of all ages and reproductive stages, care should be taken to avoid inadverted overdosing.