This paper investigates diminutives and hypocoristics in asymmetric verbal communication of Russianspeaking children, aged 13 to 16, when communicating with their pets. Observational data was collected by semi-formal oral and written questionnaires concerning these derivatives used when communicating with and talking about pets. The frequency of diminutives and hypocoristics, as well as their semantic and derivational features in the speech of boys and girls, are considered against the background of similar data of adults of corresponding gender. The gender and age differences identified in the use of diminutives and hypocoristics by respondents are statistically significant. Specifically, girls’ pet-directed speech was diminutively richer than the boys’ (both in terms of lemmas and tokens). The semantic preferences documented during diminutivization in adolescents of both genders are comparable, but differ from those of adults, as does the inventory of diminutive suffixes. The pragmatic functions of the use of diminutives and hypocoristics indicate a predominant expression of empathy, the trigger for which is a pet. The article also highlights other features of adolescent speech when addressing pets.