Parasites were studied qualitatively and quantitatively from the blood of 859 birds mist-netted between 1998 and 2003 in Singapore, Peninsular Malaysia (Cameron Highland, Fraser's Hill, Pasoh and Johor), East Malaysia (Sarawak) and Indonesia (Java). The total prevalence and relative abundance of haemoparasitic infection in the birds were evaluated by location (study area) and habitat type (e.g. primary forest). Over 50% of the examined bird species were parasitized by more than one species, in some up to five. The greater research effort was invested in Fraser and Cameron, yielding the largest numbers of birds (340) and species (55), and contributing the largest share of the recovered haemoparasites. The Fraser's Hill collection yielded the highest prevalence. The prevalence in Cameron Highlands's birds varied annually. In the latter area, Leucocytozoon infection was consistently more prevalent than Haemoproteus. In the remaining study areas, the overall prevalence was considerably lower, usually not exceeding 20% and predominated by Haemoproteus. The overall infection in Pasoh and Singapore did not exceed 6%. In the rest of the study areas Leucocytozoon prevalence was 0–3%. Our prevalence data seemed to fluctuate between years, but their magnitude could be evaluated without multi-annual studies. No particular preference in the efficacy of transmission could be demonstrated for either primary or secondary forests.