Validation study is essential to facilitate a precise and reliable clinical tool for application in practical settings. When selecting a tool for validation, researchers should consider the feasibility, cost, and purpose of using the tool in settings outside local practices. Before validating a selected tool for future implementation, researchers must take many variables into account and design a study to minimize measurement error. Some examples of considerations in this study were language barriers between tool users (researchers) and multi-ethnic participants in the nutrition evaluation process, data accuracy, and reliability. This case study provides insight into how a validation study using a cross-sectional study design was conducted at a tertiary-level hospital of a multiethnic country. The World Health Organization defines a tertiary hospital as one that has highly specialized staff and technical equipment, may offer medical education, and ranges in size from 300 to 1,500 beds.