Purpose: The purpose of this paper is to conceptualize error reporting as a strategy for informal workplace learning and investigate nurses' error reporting cost/benefit evaluations and associated behaviors. Design/methodology/approach: A longitudinal survey study was carried out in a hospital setting with two measurements (time 1 [t1]: implementation of a critical incident reporting (CIR) system; t2: three months after t1). Correlational and hierarchical cluster analyses were used to interpret the data. Findings: Positive cost-benefit correlations and negative cross-correlations were found, with no substantial changes over time. "Reporters" and "learners" were differentiated regarding error-reporting behaviors. Cost-benefit perceptions predicted membership in the "reporters" group; perception of effort costs negatively predicted an error-reporting preference. Research limitations/implications: This study was limited, in that only a questionnaire was used to collect data. Practical implications: Stressing the benefits of CIR systems should contribute to reducing employees' perception of reporting costs; thus, ease of use is a critical factor in CIR system use. Originality/value: The study empirically probes a well-established theoretical model, and various ideas for further research are suggested.