Magister Public Health - MPH / Ethiopia‟s health extension programme (HEP), which aims to improve access to and extend the coverage of health services in the country, makes use of the „model families‟ approach as a strategy for diffusing desirable health practices in the community. The approach, which emphasises prevention and health promotion, assumes that through training and accreditation „model families‟ will be able to set an example and encourage communities to embrace healthy lifestyles. However, the programme‟s implementation is not progressing at the pace originally envisaged. In addition, factors influencing the implementation of the „model families‟ approach have not, to date, been explored adequately. Thus, the aim of this study is to investigate the factors hindering or enabling the implementation of the „model families‟ approach as a strategy for improving primary health care (PHC) services in Yelmana-Denssa District (YDD).