Although Mozambique independent in 1975, public agricultural extension was not established until 1987, through the institutionalization of the National Directorate of Rural Development (DNDR). Since its establishment, human resource development has been a priority. Two approaches have been adopted by DNER for the improvement of human resource over time: the first was in-service training (non- formal and formal); and the second was to replace the elementary and certificate extensionists by hiring diploma technicians on contracts. Three evolutionary periods characterize the development of public extension in Mozambique: the establishment phase (1987-1992), the expansion stage (1993-1997), and the unified extension and PROAGRI phase (1998-2004). During each of these three phases DNER has pursued human resource development. Over the period of unified extension and PROAGRI from 1998 to 2004, DNER introduced a number of challenging goals for improving the quality of its human resources. This study was undertaken to evaluate DNER’s accomplishments in human resource development. The study addressed the role of in-service training in strengthening human resources through the acquisition of new knowledge, skills and the development of critical (analytical) thinking. This study covers only the public extension services. The data were collected during January to October 2004. Several sources of information were consulted and a questionnaire was used to collect information from DN ER staff members. The survey was carried out in January and February 2004 in 33 districts of the 66 in which public extension is currently operating. A total of 260 extensionists and supervisors were interviewed out of a total of 664 field staff members. Although human resource development and in-service training are a continuous and dynamic process, this evaluation is an overall assessment of DNER’s human resource program. The study addresses training effectiveness and relevance based on the principal courses offered to the staff over time, especially during the 1999-2004 Extension Master Plan. The results of the study show that DNER achieved impressive results in the acquisition (hiring diploma staff members on contract) of new staff but the challenging goal to have in place only diplomas as frontline extension workers by 2004 was not accomplished. The upgrading plans (1999-2004) were partially accomplished but the plan of upgrading 138 certificate extensionists to diploma level was far below expectations while results on diploma and BSc upgrading were encouraging. Low participation in-service training by staff members is also troubling. Because 35% of the sampled extensionists are still from secondary schools, special attention must be given to upgrading the knowledge and skills of those agents. One of the most important findings of the survey was the general lack of knowledge of technical messages on land preparation, soil erosion and use of fertilizers, weeding, crop pests and diseases, livestock health information and emerging issues such as irrigation, processing and marketing. Basic information needs to be collected by agricultural economists on the economics of complex interventions such as the use of treadle pumps, conservation farming and processing. Attention should be given to upgrading the technical knowledge and skills of extension staff at all levels.