This handbook gives a detailed explanation of the WHO/UNICEF guidelines for the integrated management of childhood illness (IMCI). The guidelines set out simple and effective methods for the prevention and management of the leading causes of serious illness and mortality in young children. They promote evidence-based assessment and treatment using a syndromic approach that supports the rational, effective and affordable use of drugs. The handbook gives an overview of the IMCI process and includes technical guidelines to assess and classify a sick young infant aged from one week up to two months, and a sick young child aged two months to five years; as well as guidance on how to identify treatment; communicate and counsel; and give follow-up care.