ABSTRACT. – The presence of a solitary striped dolphin (Stenella coeruleoalba) was recorded in September 2008 in the harbour of Mali Lošinj, Croatia. This species is considered to be a visitor to the Adriatic Sea, and is even more rarely seen in the northern, shallow part of this region. Whilst the animal was resident in the harbour, photo-identification and behavioural data were collected. Data on the animal’s respiration rate was collected each time the dolphin surfaced and later associated to its behavioural state. Analysis shows that the most frequently recorded behaviours were Dive (60.8%) and Rest (35.9%) while significantly less time was engaged in Travel (1.8%) and Active Aerial Behaviour (1.4%). The dolphin showed preference to certain areas of the harbour related to its behaviour. In particular it used the south-western side of the harbour, very close to the coastline, when resting, and deeper internal waters of the harbour when diving. Despite intense maritime traffic in the harbour no negative reactions to boat presence were recorded.