Abstract The ability of the domestic dog to recognise its kin, and to retain this information once acquired, was studied in this paper. Dogs were examined for their ability to recognise their siblings, offspring to recognise their mother, and mothers to recognise their offspring, using a series of two choice tests. The results revealed that, at 4–5.5 weeks of age, pups can recognise their siblings and their mother, and mothers can recognise their offspring. The preference of pups at this age appears to be strongest for their mother. Olfactory cues are sufficient for this recognition to take place. At approximately 2 years of age, and having been separated from their offspring from 8–12 weeks after their birth, mothers were able to recognise their now adult offspring and these adult offspring could recognise their mothers. Siblings could only recognise one another if they had been living with a sibling (not the test animal). Dogs living on their own were unable to recognise their siblings. Thus dogs can recognise their kin, retaining this information for a period of two years in the case of mother-offspring. It is suggested that mother-offspring and siblings are recognised by different mechanisms.