Many rural health centres in developing countries continue to treat patients without the help of any laboratory tests. The result is often inaccurate diagnosis, wasteful use of multiple drugs, and increasing drug resistance of pathogens. It is unlikely that there will ever be sufficient funds to employ a full-time laboratory worker at each of the many small remote health centres in Papua New Guinea. It is also doubtful whether staff and health extension officers who run such centres have the appropriate knowledge to adequately utilize full-time laboratory personnel. It is feasible, however, to train selected health workers in courses of three to four months' duration to perform a few simple laboratory tests part-time, in addition to their clinical duties. Suitable tests are those where the result does not require skilled interpretation. For most such tests, the result is the diagnosis. After the clinical staff have received the laboratory diagnosis, they are free to decide whether it fits the clinical picture. If so, they can then find the appropriate treatment to prescribe in standard treatment books. The present paper describes the experience in setting up and operating laboratory training for health centre staff in Milne Bay Province, Papua New Guinea. Costs and initial results of the program are discussed.