Decentralisation is one of the most common health sector reforms initiated in developing countries in the 1980-90s. Although decentralisation is often politically driven, it can significantly improve health sector performance. However, the early phase of the Philippines experience indicates that decentralisation in and of itself does not always improve the efficiency, equity and effectiveness of the health sector. Instead, it can exacerbate inequities, weaken local commitment to priority health issues and decrease the efficiency and effectiveness of service delivery by disrupting the referral chain. Such effects pose a particularly serious threat to accessibility and delivery of reproductive health services, some of which (e.g. family planning) are controversial and thus susceptible to local pressures, and others of which (e.g. emergency obstetric care) require a functioning and effective health system. Moreover, those undertaking decentralisation need to take account of the impacts of non-health factors as well as other reforms that interact with decentralisation to affect accessibility, affordability and quality of services, including for reproductive health. The Philippines experience also demonstrates that authority should be shared between the centre and local units in order to achieve national health objectives and respond to local health needs. Adjustments must be made during implementation to correct for both emerging and pre-existing problems.