This study seeks to investigate the type of social problems facing children of unknown parentage in foster families in the Governorate of Muscat, and to identify difficulties encountered by families taking care of this category of children, their ability to deal with the social problems they face, and the role of alternative-care professionals in providing support and assistance to these families and the challenges they face. In this study, the researcher has used a descriptive method, and the study was applied to 40 children of unknown parentage of age 12 to less than 18 years, in 38 foster families, and nine workers in the field of alternative-care services. The data collection tools included a questionnaire for children of unknown parentage, an interview guide for foster families, and an interview guide for officials and employees involved in the field of services to foster families in the Ministry of Social Development. The study resulted in a number of important findings. No big problems can be noted regarding social problems facing children of unknown parentage. This is due to the family efforts in taking caring of those children. This can be related to the fact that the majority of foster families usually do not tell the children about their real social situation. It should however be indicated that this study has revealed a few social problems, including the inability of some children to cope easily with others, low levels of educational achievement, and the practice of lying amongst the children. Moreover, the study results show that there are difficulties facing foster families while providing care for the children. These include the difficulty of families to gain access to sources of information about this category of children, causing them not to tell the child about his/her real social situation due to lack of knowledge of the right way to tell him/her, and the inadequate services provided to the child and foster families. With regards to difficulties facing workers in the field of services to foster families, the study demonstrated that they do not receive proper training that helps them in practicing their duties. It also highlighted the lack of judicial immunity needed by workers during their field visits, and the lack of specialized studies in the field of alternative-care which hindered our understanding of the reality of alternative-care in the Sultanate of Oman. Based on the findings of this study the researcher has developed some recommendations that may help in tackling problems facing children of unknown parentage. These include, for example, raising the level of care provided to the children, making use of media and civil society organizations to promote the culture of nurturing (foster), and creating some sort of cooperation and interaction between governmental organizations to accommodate this category of children. They also include developing recommendations to assist in facing difficulties encountered by families in providing care for the children of unknown parentage. Among these are being faster in dealing with nurturing (foster) requests, setting up regular meetings between foster families and officials to identify the most important challenges faced by families, and to find appropriate ways to address them. There are also recommendations that could help workers in implementing their duties in a proper way. These include giving them judicial immunity, the preparation of awareness programs for families and society in general, as well as the cooperation with specialized research centers, and supporting researchers. The researcher has also developed a proposal about the role of the social worker in the area of alternative-care.