WHO and partners have been working towards devising an agenda, an action plan, tools and guidelines to increase access to appropriate medical devices. This document is part of a series of reference documents being developed for use at the country level. The series will include the following subject areas: * policy framework for health technology* medical device regulations* health technology assessment* health technology management* needs assessment of medical devices* medical device procurement* medical equipment donations* medical equipment inventory management* medical equipment maintenance* computerized maintenance management systems* medical device data* medical device nomenclature* medical devices by health-care setting* medical devices by clinical procedures* medical device innovation, research and development.These documents are intended for use by biomedical engineers, health managers, donors, nongovernmental organizations and academic institutions involved in health technology at the district, national, regional or global levels.Needs assessment is a complex process, incorporating a number of variables, that provides decision-makers with the information necessary to prioritize and select appropriate medical devices at a national, regional or hospital level. This document describes and illustrates the objective, the general approach and the process of such a needs assessment. The main section, Specific Approach (Section 4), demonstrates in seven steps how to identify related needs, consider the requirements of baseline information, analyze the gathered information, appraise the options, and prioritize the specific requirements. Tools are being continuously developed to support this decision-making process, and this document also includes information on useful tools that will help in the execution of these steps.