The determination of the religion of the child has become an issue when one of the parents converts into Islam. This often results to disputes on the custody in court, which could give a grave impact on the welfare and the best interest of the child. In the Malaysian legal setting where both the civil and syariah courts co-exist in their respective spheres, there are nevertheless arguments on the overlapping jurisdictions or grey areas in respect to issues such as conversion and family law. This article analyses the decision of the Federal Court in the case of�Indira Ghandi A/P Mutho [2018], its background, issues of judicial review, the jurisdiction of the Syariah courts, registration of conversion, consent from parent(s) and decisions from other related cases. It also studies the development of Islamic law on the issue of conversion, which includes juristic views from the major school of thoughts (mazahib), contemporary Islamic rulings (fatwa) and the official rulings of the National and State Fatwa Committee. This article provides suggestions for the issue in question, from both legal and shariah perspectives.