The correlation between self-efficacy, literacy and behaviour has the potential to have a long lasting impact on students’ academic achievement, psychosocial development, and wider societal success. While each of these constructs have been investigated individually, and their interaction with each other researched, little research has looked at all three simultaneously, particularly within the first 3 years of students’ formal education in Aotearoa New Zealand. The focus of the current research was to investigate the association between self-efficacy, literacy development, and behaviour in children from school entry through to their third year of school in Aotearoa New Zealand. Data from a longitudinal study (Chapman, Arrow, et al., 2018) was analysed which included reading self-efficacy, phonological processing, pseudoword reading, spelling, whole word reading, inattentive behaviour, hyperactive and moody uncooperative behaviour. Results indicated that inattentive behaviour was negatively associated with literacy across the first 3 years of school, while self-efficacy was positively correlated with literacy. Inattention at the end of Year 1 was positively correlated with self-efficacy in the third year of school. Inattention was the most highly correlated behaviour variable with self-efficacy and literacy, above hyperactivity and moody uncooperative behaviour. Overall, the results suggest that low literacy achievement early in school may contribute to low self-efficacy and high levels of inattentive behaviour, all of which have a negative impact on literacy achievement throughout the school years.