The aim of the present study was to validate a reduced Spanish version of the Negative Acts Questionnaire (NAQ; Einarsen & Raknes, 1997). This instrument, which has been widely used in various studies, was developed to measure workplace bullying. Two samples, the first comprising 352 employees from 11 organizations, and the second comprising victims of bullying who were recruited from 15 Spanish associations against bullying, participated in the study. Exploratory factor analysis conducted with the data from the first sample revealed a two-factor solution that accounted for 63.3% of the total variance. The data from the second sample were used for confirmatory factor analyses to compare three structure models of the NAQ (one factor, two independent factors, and two correlated factors). The results indicate that the correlated two-factor model provided the best fit to the data (χ2/df = 2.1, CFI = .93, GFI = .95, RMR = .04, RMSEA = .06, AIC = 215.4). Reliability analysis showed that this 14-item Spanish version had high internal consistency. Significant correlations between the NAQ and its dimensions and diverse health and perceived stress scales were found, which provided evidence of construct validity. Taken conjointly, the results of this study support the use of the Spanish version of the reduced NAQ in future research.