This study aims to investigate the followings; i) what the mothers of adults with developmental disabilities experience when they use day care services ii) what it means for them to use day care services iii) the meaning of situational context of using daycare service. To analyze these matters, the qualitative case study was conducted for the mothers of adults with developmental disabilities using the Day Care Center for Developmental Disabilities. Seven mothers of adults with developmental disabilities using Busan Regional Day Care Center were interviewed in depth and the collected data were analyzed. The data collected from seven cases were analyzed individually to identify important issues for each case, and finally, we analyzed the common contents in all cases. The issues identified from the analysis are as follows; ‘Stuffy but Unable to Speak’, ‘Confusion about “Sex”’, ‘Struggle to Survive’, ‘the reality of being alienated from people and information’, ‘Nevertheless Eager’, etc. Based on the results of this study, the policies and practice guidelines related to day care services for the individuals with developmental disabilities were suggested.