Introduction: Nutritional risk screening in oncology patients aims to timely identify malnutrition and muscle depletion to improve prognosis. The Protocol for Nutritional Risk in Oncology (PRONTO) is a simple and effective tool for this purpose, whose transcultural adaptation and validation are necessary for its application in Colombia. Objective: To carry out the initial phase of the linguistic adaptation of the PRONTO Protocol into Spanish and evaluate its semantic and conceptual equivalence through expert review in the Colombian context. Methods: This study corresponds to Phase I of the cross-cultural adaptation of the PRONTO screening instrument for the Colombian population was conducted through translation-back translation, expert review, and content-validity assessment. Exploratory analyses were performed to assess content validity by a panel of experts using a Likert scale, Aiken's V, and I-CVI and S-CVI indices. Reliability was estimated using Cronbach's alpha. Results: The adapted protocol demonstrated semantic and conceptual equivalence with the original version. The scale-level content validity index (S-CVI/Ave) was 0.887, indicating strong overall agreement among experts. All items showed perfect individual content validity (I-CVI = 1.000). Aiken's V values were also high across domains. Cronbach's alpha was 0.577, consistent with an early-stage validation of a brief screening tool. Ninety-three percent of experts considered the tool easy to apply in clinical practice, highlighting its usefulness for detecting nutritional risk in oncology patients. Conclusion: A Spanish version of PRONTO was obtained, equivalent to the original and with adequate content validity; psychometric validation in the target population is recommended to confirm its clinical use.