This study, “Child Labour in Nigeria, and its economic implication”, is aimed at investigating the existence of child labour, its causes, constraints and economic implications and how to eradicate it with particular interest in Calabar Municipality, Cross River State, Nigeria. Calabar Municipality is a tourist center and has witnessed massive population growth since 1999. This increase in population has forced many families to be engaged in inhuman activities to avoid destitution, scavenge for existence that could best be described as child labour. A stratified random sampling method was carried out in 500 respondents who are found to be involved in child labour through interviews, issuance of questionnaires and focused group discussions. The data obtained from the field were analyzed using Simple Percentages (%) and Chi-square (X2) to test the level of significant difference. The analyses revealed that 52% child labour is currently practiced in Calabar Municipality. The study also showed that there is a significant relationship between child labour and the following variables; poverty, unemployment and school dropout at 0.05 level of significant. This indicates a negative effect on economic growth in Nigeria as the future of the country is at risk. I therefore recommend that government should come up with legislations that will tackle the problem of poverty and unemployment in Nigeria, effective implementation of policy that would outlaw all forms of child labour, establish a compulsory, quantitative and qualitative free or minimal cost education for all Nigerians and finally, the National, State and Local Government Orientation Agencies should be mobilized to carryout extensive inspections in schools to reduce the number of school drop-out. Keywords: Child Labour, Child Abuse, Calabar Municipality and Economic Growth