An ecological perspective was used to examine non-suicidal self-injurious behaviours among two distinct non-clinical populations: adolescents and emerging adults. Data was collected online from 152 females primarily from North America. The main reason provided by both age groups for engaging in acts of non-suicidal self-injury (NSSI) was to stop bad feelings. Self-harm was done mainly by cutting the wrists, arms, or other area(s) of the body. Among emerging adults, significant relationships were found between NSSI, and depression and anxiety. For both groups, self-esteem was a negative predictor of NSSI. Overall, participants perceived higher levels of warmth and acceptance, and behavioural knowledge from their mothers than from their fathers. Parental warmth and acceptance was a negative predictor of self-harm. Participants most often disclosed their self-injury to a friend and solicited help for their self-injury from friends or a family member, rather than from professionals.