OBJECTIVE: To present a review on the methods for the assessment of child and adolescent nutritional status, emphasizing anthropometry and the various methods for the assessment of body composition; pointing out their advantages, limitations and risks. METHODS: Chapters of textbooks, theses, and articles relevant to the topic, as well as personal files and authors previous publications were selected. RESULTS: Anthropometry, which consists of the assessment of physical dimensions and global composition of the human body, has been regarded as the most frequently used isolated method for nutritional diagnosis, especially in childhood and adolescence, due to its ease of use, low cost and innocuousness. The most frequently adopted measurements aim at determining body mass, expressed by weight; linear dimensions, especially height; body composition and reserves of energy and proteins, estimated through subcutaneous fat and muscle mass. Laboratorial methods especially developed for the assessment of body composition are presented here. The justification for the use of methods that expose children and adolescents to ionizing radiation is also presented. CONCLUSIONS: On defining methods for the assessment of nutritional status, we should select those that better detect the nutritional deficiencies we want to correct, also taking into consideration their costs, level of personal skill required for their proper application, necessary time for application, acceptability by the studied population and possible health risks.