Increased international awareness of the need to provide accessible essential or emergency obstetric and newborn care in developing countries has resulted in the recognition of new training needs and in a number of new initiatives to meet those needs. This paper reviews experience in this area so far. The first section deals with some of the different educational approaches and teaching methods that have now been employed, ranging from the traditional untheorized 'chalk and talk', to competency-based training, to theories of adult learning, problem solving and transferable skills. The second section describes a range of different types of indicators and data sources (learner assessments, user and community assessments, trainer assessments and institutional data) that have been used in the assessment of the effectiveness of such training. The final section of the paper draws together some of the lessons. It considers evaluation design issues such as the inclusion of medium and long term evaluation, the importance of methods that allow for the detection of iatrogenic effects of training, and the roles of community randomized trials and 'before, during and after' studies. Issues identified for the future include comparative work, how to keep training affordable, and where training ought to lie on the continuum between straightforward technical skills acquisition and the more complex learning processes required for demanding professional work.