The Stressors about Practicum Inventory, a self-report measure of perceived stressors about the practicum, was designed to provide those responsible for the training of primary school teachers with an informative, inexpensive and psychometrically sound tool. The present study describes the development and validation of the 94-item inventory in a sample of 138 Greek primary student teachers. It also investigates its initial factor structure and reliability. The scale was administered both before and after a four-week period of practicum. Content validity was examined using a panel of experts and student teachers, whereas convergent validity was assessed with the use of a measure of neuroticism. Factor analyses revealed four sources of perceived stress. No gender differences were found. However, the experience of the practicum significantly reduced student teachers' perceived stress. All perceived stressors were moderately correlated with neuroticism, but after the practicum the size of the correlations was reduced.