The Student Career Construction Inventory measures students' adapting behaviors. The present study validates this inventory in a sample of 314 Portuguese college students. Measurement confirmatory factorial analysis indicates better fit for the 18-items measurement model, comparing to the 25-items model. Reliability and criterion-related analyses evidence the inventory validity and use. Structural model path analysis shows significant relations between measures of adaptability, adapting behaviors, and vocational identity results. This indicates that self-regulatory resources may drive career decidedness. While further longitudinal studies are needed to test the inventory and model's predictive validity, our results provide developments to the literature on career measurements.