This study set out to identify the most important needs of hospital patients on surgical and medical wards and to assess the ability of nurses to identify these needs. The population consisted of 92 Finnish patients and 69 Finnish nurses. The study was carried out using a questionnaire designed on the basis of the need theory presented by Yura and Walsh. The results of the statistical analyses were presented in the form of frequencies, cross-tabulation and chi-square tests. The patients' most common needs were related to vital functions (44%), followed by those related to functional health status (38%) and environmental needs (36%). The last item on the list of expressed needs concerned reactions to functional health status (31%). Over 70% of the surgical patients suffered from problems related to sleep and rest. Less than 60% of them suffered from acute pain. Medical patients, in turn, had more frequent needs related to vital functions than did surgical patients. Three out of four medical patients suffered from acute pain. Sleep and rest disturbances, stress, bad mood and listlessness were also common problems. The nurses underestimated all patient needs, apart from environmental needs, which they regarded as the main concern of patients. There was a statistically significant difference between patients ‘and nurses’ assessments for 38% of all needs. Moreover, there were differences in assessments between the surgical and medical wards included in the study.