Infant measurements such as weight, head circumference, chest circumference, abdominal circumference, and length are frequently obtained in clinical practice in the immediate postbirth period to evaluate fetal growth and provide a baseline for future measurements. Some of these other measurements, such as mid-arm circumference and thigh circumference measurements, are more commonly used in research to determine an infant's level of under- or over-nourishment or to try and determine a valid proxy for weight measurements where accurate infant scales are not available. This article describes the history of infant anthropometric measurements, and how these measurements are obtained and used in clinical practice. The reliability of these measurements is summarized in a comprehensive table. Copyright 2002, Elsevier Science (USA). All rights reserved.