Aims: The prevalence of childhood obesity is a significant public health concern. Family-based intervention programmes have incorporated behavioural, dietary and lifestyle changes which are theoretically underpinned. Few reviews to date have determined the effectiveness of family-based interventions in reducing childhood obesity on a long-term basis. The aim of this research was to systematically review the short and long term effectiveness of family-based interventions in reducing childhood obesity among children aged 2-18 years old living in the UK. Method: An electronic search was conducted using DISCOVER, PUBMED, SCIENCE DIRECT, SPORT SCIENCE and GOOGLE SCHOLAR and by searching reference lists using a predefined search strategy. The review included a randomised controlled trials, quasi-randomised trial, cohort studies and programme evaluations. The primary outcomes measures included BMI, BMI z-score/percentile, waist circumference and weight in kg. Risk of bias and quality of evidence of selected studies were assessed using Effective Public Health Practice Project Tool. Results: The review identified 3100 articles of which 10 met the inclusion criteria. Out of the ten studies, five were randomised studies, three were cohort studies and two were programme evaluations. The participants’ ages were between 4 and 18, intervention duration ranged from 8 weeks to 1 year and follow-up period ranged between 3 months and 2 years. All the reviewed studies incorporated more than one family-based interventions- lifestyle, behavioural, dietary and physical activity; nine out of ten studies established parental involvement but three studies reported active parents’ participation. Conclusions: Family-based interventions showed varying degree of changes in adiposity of the participant children on a short-term basis and a promising advantage of a long term effect. However, the long lasting benefits of family-based weight management programme lacks strong evidence from high methodological quality studies as well as limited proof on the link between parents involvement and the effectiveness of the programme.