Background: Smart phone devices have become a potentially addictive behaviour. Parental smart phone addiction may probably have far reaching consequences on the behaviour of children.Objectives: To study the association between parental smart phone addiction and behavioural problems in children.Method: The study involved 500 children aged 2-12 years and their parents visiting the outpatient department (new and follow up cases) of a tertiary care hospital in Durgapur after receiving institutional ethical committee clearance. ”Smart phone compulsion test” was given to each parent to enquire about smart phone usage practices after taking informed consent. The parents were also asked to fill in the Paediatric Symptom Checklist-17 to know about behavioural problems of their children. Each responded questionnaire was assigned a specific serial number. Data from matched sets of questionnaires as per serial number were analysed using Chi-square test. p<0.05 was taken as significant. Odds Ratios (OR) and Relative Risks (RR) were also computed.Results: Smart phone addiction in parents was significantly associated with overall behavioural problems (p<0.001), internalization (p<0.001) and externalization (p<0.001) in children. No significant association was seen with attention problems. Computed values of RR and OR were also indicative of the same.Conclusions: Smart phone addiction in parents was significantly associated with behavioural problems in children.Sri Lanka Journal of Child Health, 2021; 50(2): 266-271