Purpose: The purpose of this paper is to investigate the relationship between online friend networks and the mental well-being (MWB) of adolescent males. Design/methodology/approach: The study used a mixed methods approach: first, questionnaire involving a validated MWB scale and questions regarding online friendship to 14-15 year old males (n=521); and second, focus group interviews (n=8) of between six and eight members three months later. Findings: Positive and negative associations were recorded between online friends and well-being. A positive relationship (p < 0.05) was found between the number of online friends and well-being scores. However, higher numbers of online friends were also associated with increases in negative online experiences namely, receiving embarrassing posts online or risky activities such as, chatting frequently with strangers. Online friends may influence perceptions of social support, status and belonging, each of which may contribute positively or negatively to well-being. However, by increasing these perceptions, online friends may cause additional distress when their presence does not provide tangible support during a crisis period. Originality/value: Online friends provide the context to which young males explore and negotiate the online world. To date, little mixed methods research has focused exclusively on the MWB of online friends. Policy makers could do well to consider the growing prominence of online social networking and produce targeted programmes to educate young people on the benefits and pitfalls of building large online “friend” networks.