The study assessed the self-reported frequency and quality of use of the Paediatric Standard Treatment Book by staff in urban clinics and rural health centres. 61 of the 88 nursing officers and 44 of the 89 community health workers in 9 urban and 4 rural health settings completed written questionnaires on their use of the Standard Treatment Book. The survey participants were also assessed on the management of three case scenarios of common clinical conditions. Whilst 69% of the participants reported daily use of the book, only 51% indicated that they always followed the guidelines. Performance in the case scenarios was poor. Although 87% made a correct diagnosis in the most straightforward case, only 38% indicated complete treatment and only 36% indicated complete and correct advice. In two more complex scenarios less than 30% of the participants made correct diagnoses and less than 10% indicated complete treatment and advice. 75% of the study group wanted inservice training on the use of the book; the majority of these said that doctors should give this training. 79% thought that the book could be improved. Many of the participants felt that more topics and more flow charts should be included. Whilst nursing officers and community health workers regard the Standard Treatment Book (STB) as important, many do not make optimal use of it. Knowledge of appropriate advice to give parents regarding their child's illness was particularly poor. Given the low scores of health workers on case scenarios involving children with more than one presenting problem, the use of the STB appears to be essential for management of most severely ill children presenting to health facilities in Papua New Guinea. Doctors, especially paediatricians, have an important role to play in stressing the importance of the book, in teaching health workers to use it correctly and in emphasizing an integrated approach to the management of sick children. The study incorporated an assessment of health facility infrastructure and equipment. All facilities needed maintenance work, and more than half had significant deficiencies in equipment and drug availability. Medical staff supervision and support of primary health staff is important and should include increasing and improving the use of the Standard Treatment Book. Such support should also aim to improve the working environment and health facility resources. This would substantially improve the service provided.