The aim of the study was to discover how much Finnish nursing staff know about the pain experienced by premature babies and about pain assessment. The types of helping methods used by caregivers in the nursing of premature babies were also studied. A semistructured questionnaire was sent in autumn 1995 to all registered nurses, practical children's nurses and medical laboratory technologists who take heel blood samples (n = 280) working in paediatric intensive care units in all Finnish university hospitals. The response rate was 70.4%. The structured questions were processed quantitatively at Kuopio University with the SPSS/PC+ data processing program (SPSS, Chicago, IL, USA), and the open questions were processed using quantitative content analysis. The results indicate that the respondents have rather extensive knowledge about the pain experienced by premature babies, pain assessment, pain management and about nursing and helping methods. Pain was assessed mostly on the basis of behaviour and physiological changes, and only infrequently on the basis of biochemical changes. The respondents described the helping methods they use in considerable detail. The most common was to increase the baby's feeling of security. The answers to the open questions revealed that the actions used by the respondents in pain assessment and pain management were not completely consistent with their knowledge. The results demonstrate that caregivers do not use their knowledge adequately in their pain management practices. Future studies should observe the three groups of caregivers in order to discover how they treat premature babies' pain.