Four studies involving over 1300 workers were conducted to develop a psychometrically adequate Work Stress Inventory. Its final form has 40 items, each rated on a 5-point scale for intensity and frequency of stress. Items cover organizational stress and job risk, shown to be factorially distinct. Intensity, frequency, and composite (I x F) indices for these two scales were found to have high internal consistency and good test-retest reliability. As predicted, frequency of organizational stress was moderately related to anxiety, satisfaction with supervision and work, and organizational commitment. Frequency of job risk was related only to anxiety and satisfaction with work. Intensity, although highly correlated with frequency, had lower correlations with other measures.