The tick Ixodes uriae is widespread in subantarctic areas. This tick species parasitises a large number of seabird species and may affect their population dynamics. Adult king penguins are significant hosts for I. uriae in Crozet Archipelago. We compared the body mass, haematocrit level and behaviour during incubation according to tick infestation. Tick infestation had no effect on the body mass, haematocrit or behaviour of incubating penguins. Contrary to what might have been expected, birds breeding in the infested area did not show a lower fidelity to that area the next breeding season in comparison to birds breeding in the non-infested area. Survival was not different between the two groups over the following 32 months.