This paper demonstrates how a health authority can use personnel records of nurses' working histories as an effective tool in manpower planning. Suggestions are given as to how these histories might be analysed and interpreted. Methods described range from the use of simple summary statistics and graphical methods to advanced statistical modelling techniques. Data from a study by researchers at the Centre for Applied Statistics and Department of Sociology at Lancaster University are used to give examples of these approaches. A description is also given of the practical difficulties experienced when attempting to extract the appropriate data from the health authority's personnel records.