Assessment tools must be investigated for reliability, validity and feasibility before being implemented. In 2013, the Australian and New Zealand College of Anaesthetists introduced workplace-based assessments, including a direct observation of a procedural skills assessment tool. The objective of this study was to evaluate the psychometric properties of this assessment tool for ultrasound-guided regional anaesthesia. Six experts assessed 30 video-recorded trainee performances of ultrasound-guided regional anaesthesia. Inter-rater reliability, assessed using absolute agreement intraclass correlation coefficients, varied from 0.10 to 0.49 for the nine individual nine-point scale items, and was 0.25 for a 'total score' of all items. Internal consistency was measured by correlation between 'total score' and 'overall performance' scale item (r = 0.68, p < 0.001). Construct validity was demonstrated by the 'total score' correlating with trainee experience (r = 0.51, p = 0.004). The mean time taken to complete assessments was 6 min 35 s.