Aim: To estimate the validity and reliability of the Leadership and Management Inventory, a tool to measure the skills and abilities of first-line nurse managers. Background: The decision to develop an inventory reflects the need for an instrument that can measure the various skills and abilities first-line nurse managers should possess. Method: Factor analysis was conducted and internal consistency initially estimated on data from 149 registered nurses; a second sample of 197 health care personnel was used to test these results. Results: Principal component analysis of the first sample resulted in a preferred three-factor solution that explained 65.8% of the variance; Cronbach's alpha coefficient varied between 0.90 and 0.95. Analysis of the second sample also resulted in a three-factor solution that explained 64.2% of the variance; Cronbach's alpha coefficient varied from 0.88 to 0.96. For both samples, the factors were labelled 'interpersonal skills and group management', 'achievement orientation' and 'overall organizational view and political savvy'. Conclusion: Results indicate that estimates of validity and reliability for the Leadership and Management Inventory can be considered acceptable. Implications for nursing management: The Leadership and Management Inventory can be used when first-line nurse managers' leadership and management skills and abilities are to be measured.