Daily activity of Eurasian otters (Lutra lutra) was recorded along the coast of Shetland, UK, in the summer of 1984. Data of three otters fitted with radio-transmitters were analysed in detail. Compared to sea otters (Enhydra lutris), these otters spent up to 4.5 times less time per day hunting (12%), but devoted the same time per day to grooming (6%). Hunting bouts (mean 13.7 min) were interrupted by resting bouts (17.0 min) during which the otters groomed (9.1 min) and slept (6.6 min). The duration of the resting bout was significantly correlated (P < 0.05) with that of the preceding hunting bout. Also, the time spent grooming was correlated with the encountered underwjter pressure (P < 0.05). The functions of resting and grooming probably include reestablishing air in the fur and rapid recovery after diving; also avoiding encrustation of salt on the fur might be important.