This paper compares the use of slang by the teenagers represented in The Corpus of Kaunas Teenage Language and The Bergen Corpus of London Teenage Language. The comparison shows that teenage slang is a psycho-social phenomenon representing three major categories, which exhibit gender-based differences; that psycho-social factors influence the creation and function of gender- and age-specific slang; that the prevalence of boys’ slang contributes to the masculine characteristics of slang; and that the psycho-social factors that stimulate the teenagers’ emotions affect the use of slang, giving rise to offensive and humorous slang. Both groups identify themselves and their groups by using slang, but while the 10–13 year-olds are the most active users of slang in Kaunas, the distribution among the London age groups is more even.