Summary Introduction The Skin Cancer Index (SCI) is the first specific patient‐reported outcome measure for patients with cervicofacial nonmelanoma skin cancer. To date, only the original English version has been published. Objectives To develop a Spanish version of the SCI that is semantically and linguistically equivalent to the original, and to evaluate its measurement properties in this different cultural environment. Material and methods A cross‐sectional study was conducted of the cultural adaptation and empirical validation of the questionnaire, analysing the psychometric properties of the new index at different stages. Results Of 440 patients recruited to the study, 431 (95%) completed the Spanish version of the SCI questionnaire, in a mean time of 6·3 min (SD 2·9). Factor analysis of the scale revealed commonality and loading values of < 0·5 for three of the 15 items. The remaining 12 items converged into two components: appearance/social aspects (seven items) and emotional aspects (five items). Both domains presented a high level of internal consistency, with Cronbach's alpha values above 0·8. The convergent–discriminant validity analysis produced correlations higher than 0·3 for the mental component of the Short Form Health Survey‐12v2 Health Questionnaire (correlation coefficient 0·39) and the Dermatology Quality of Life Index (correlation coefficient −0·30). In the test–retest, nine of the 12 items produced a weighted kappa value exceeding 0·4, and for the remaining three items, the absolute agreement percentage exceeded 60%. Conclusions The Spanish version of the SCI quality of life scale has been satisfactorily adapted and validated for use in Spanish‐speaking countries and populations. What's already known about this topic? The first questionnaire specifically focused on the quality of life for patients with cervicofacial nonmelanoma skin cancer, the Skin Cancer Index (SCI), has been developed recently in the U.S.A. This questionnaire represents a valuable tool not only in clinical practice but also in the field of epidemiological and clinical research. At present only the original English version is available. What does this study add? We have obtained the first Spanish version of the SCI that is semantically and linguistically equivalent to the original and that guarantees validity and reliability. This new version will enable use of the SCI in research on quality of life of patients with nonmelanoma skin cancer to other countries and to Spanish‐speaking population worldwide.