The purpose of our study was to assess if the Polish translation of the European Organisation for Research and Treatment of Cancer (EORTC) Colorectal Cancer (CRC)-Specific Quality of Life Questionnaire (QLQ-CR29) is an acceptable and psychometrically valid measure to collect quality of life (QoL) data in Polish patients with CRC for use in clinical trials and clinical practice. A total of 150 patients undergoing treatment for CRC were prospectively enrolled in the study. Psychometric assessment of the translated QLQ-CR29 structure, reliability, convergent and divergent validity, and clinical validity was subsequently performed. The Cronbach's alpha coefficient ranged from 0.70-0.89, indicating acceptable internal consistency. For test-retest reliability, the ICCs for each item ranged from 0.59-0.91, with exceptions for urinary incontinence and dysuria, indicating good to excellent reproducibility. In multi-trait scaling analyses, the criterion for item convergent and divergent validity was satisfied. The correlations between the EORTC QLQ-CR29 and QLQ-C30 scales were mostly low (r < .40), with a few items demonstrating higher correlations. The known group comparisons analyses demonstrated the ability of the questionnaire to distinguish between patients’ differing age, stoma status, and treatment intent. The Polish translation of the QLQ-CR29 is a psychometrically reliable and valid tool. The results of this study are congruent with that of EORTC validation.