Short-term effectiveness of the International Child Development Programme (ICDP) for parents in the general population has been studied. The aim of this paper was to investigate the longer term impact of the ICDP programme on parents looking for sustained changes 6-12 months after the programme. For this, a non-clinical caregiver group attending the ICDP programme (N = 79) and a non-attending comparison group (N = 62) completed questionnaires on parenting, psychosocial functioning, and child difficulties before, on completion and 6-12 months after the ICDP programme. Analyses compare changes in scores over time. The results revealed that the ICDP group showed significantly improved scores on parenting measures, less loneliness, and trends towards improved self-efficacy compared to the comparison group 6-12 months after programme completion. The ICDP group also reported that their children spent significantly less time on television and computer games and a trend towards fewer child difficulties. Key positive effects sustained over time but at a somewhat lower level, supporting community-wide implementation of ICDP as a general parenting programme. It is concluded that more intensive training with follow-up sessions should be considered to sustain and boost initial gains.