Assessing the pediatric patient is one of the most challenging and stressful tasks for nurses. Assessment is a key component of nursing practice, required for planning and provision of patient and family centered care through nursing process. Assessment is an important part of the nursing process. Assessment includes not only physiological data, but also psychological, sociocultural, spiritual, economic, and life-style factors as well. This chapter covers the importance of assessment in pediatric patients, skills used for assessment, assessment of pediatric patient, admission assessment, developmental assessment, assessment of nutritional status, purposes of nutritional assessment, and various techniques with different approaches. The assessment of nutritional status involves various techniques with different approaches. The assessment method includes dietary history, clinical examination, anthropometrical measurement, biochemical evaluation and laboratory tests, functional assessment, and radiology.