The overall aim of this thesis was threefold; first, to explore resources associated with work-life balance (WLB), with a focus on the work and private lives of human service employees. Second, to develop a workplace health promotion (WHP) intervention with a WLB focus. Third, to explore the participants’ experiences of the developed WHP intervention done in the workplace. A mixed method approach was used to answer the research questions. The thesis is based on two qualitative studies, one quantitative study and one paper that describe the content and development process of the intervention. The qualitative studies were based on individual interviews and focus group interviews (I, IV). Thirteen semi-structured individual interviews and two focus group interviews were conducted with home help service nurses in Sweden (I). Eight focus group interviews and eight semi-structured individual interviews were conducted with participants in the intervention (IV). A qualitative content analysis was used for the analyses in the qualitative studies. The quantitative study was based on a questionnaire survey to a population of two municipality departments (n = 631, response rate 76%) (II). A linear regression model and logistics regressions models were used for the analyses. The planning and development of the intervention was done using an intervention mapping approach (III). The findings showed a complex picture of resources related to WLB. Resources could be found in the work domain, the private domain and the individual domain (I, II). In the work domain, it seems to be important to have a positive time experience and a meaningful job, but also to work part-time and do shift work. In the private domain, a positive time experience and social support was highlighted. Individual resources such as good health, well-being, reflection and satisfaction with one´s life situation were seen as essential to WLB. The development process of the intervention resulted in the “Balance in Everyday Life Empowerment” (BELE) program (III). The findings showed that a majority of the participants taking part in the BELE program experienced a process of change, often enhanced by an increased awareness, support and inner strength, which promoted well-being and balance in their everyday life (IV). In conclusion, it seems important to use a holistic approach where resources in the employees’ overall life situation are included for the enhancement of WLB. The BELE program was an attempt to contribute to WHP with a WLB focus, and the result indicates that the program was effective with regard to promoting employee well-being.