- Objectives: Brief screening instruments are useful in busy clinical practice to identify those requiring further assessment. This study aims to translate and validate a Portuguese version of the four-item Zarit Burden Interview (ZBI-4) to identify caregiver burden in a community-based sample in Northern Portugal.Methods: We collected data from 203 informal caregivers of community-dwellers aged ≥80 years. Internal consistency and factors were measured using Cronbach's alpha. Pearson's correlation was used to examine construct validity against negative and positive aspects of caregiving from the Caregiving Appraisal Scale. Discriminative ability was evaluated from the area under the receiver operating characteristic curve (AUC). Optimal cutoffs were calculated using Youden´s Index.Results: The internal consistency of the Portuguese version of the ZBI-4 was good (alpha = 0.71). Concurrent validity was acceptable, showing strong correlation with the negative (rho = 0.66) and medium correlation with positive (rho = -0.33) aspects of the Caregiving Appraisal Scale. Discriminative accuracy for caregiver burden was also good (AUC = 0.86). Youden's index produced an optimal cutoff of ≥7 points for burden.Conclusions: The Portuguese version of the ZBI-4 screen demonstrates good psychometric properties.Clinical implications: These results show the utility of the Portuguese version of ZBI-4 as a short screen for caregiver burden for use in the community to facilitate rapid screening for this important and complex stressor.