Forest birds were surveyed on the islands of Flores and Sumbawa, Indonesia, in July-September 1993. Assessments were made of the conservation status and habitat requirements of the restricted-range, threatened, and near-threatened species. Semi-evergreen rainforest was found to be more important than moist deciduous monsoon forest for the conservation of these species, but such habitat is being rapidly degraded at mid-altitudes and in the lowlands. Moist deciduous monsoon forest is still widespread in the lowlands but it is also being degraded by human activities. Only one significant protected area exists in the region: Taman Nasional Komodo. This harbours an important population of Yellow-crested Cockatoo Cacatua sulphurea but it is too dry o t support any semi-evergreen rainforest. Ten of the 24 restricted-range species found on these islands are of particular conservation importance mainly because of combinations of intolerance of degraded habitat, dependence on semi-evergreen rainforest, restriction to the lowlands, and low population densities. The highest priority species are Flores Monarch Monarcha sacerdotum and Wallace's Hanging-parrot Loriculus flosculus, which were only found in semi-evergreen rainforest at about 450-950 m at one site in the Tanjung Kerita Mese proposed protected area in south-west Flores. Effective protection of this site is urgently required in order to help secure the future of these species. Recommendations are presented for the protection of further areas on Flores and Sumbawa.