Background: The uncontrolled, inappropriate or excessive use of the mobile phone can give rise to social, behavioural and affective problems. Mobile phone addiction has emerged as a challenging public health issue. The aim of the study was to find out the proportion and associated factors of mobile phone addiction among children aged 5-12 years.Methods: A cross-sectional study was conducted among 222 children in the age group of 5-12 years. Data collection was done using a semi-structured questionnaire and outcome variable measured using the diagnostic criteria developed by Lin et al. Chi-square test and binary logistic regression was done to find out the association between exposure and outcome variables.Results: 42.3% of children aged 5-12 years had mobile phone addiction. Factors like higher socio-economic status of the family, educated father, children with normal weight for age, presence of visual problems, headache, poor concentration and disturbed sleep were found to have statistically significant association with the mobile phone addiction. The predictor variables found on regression were higher socio-economic status, children with normal weight for age, disturbed sleep and poor concentration.Conclusions: This study found nearly half of the children belonging to 5-12 years was addicted to mobile phones which is higher than expected and is a serious matter for the growing children. The risk factors found in the study are modifiable to an extent and hence regional and national level strategies has to be implemented in accordance with the available studies to tackle this public health problem.