This is an ethnographic study concerning the challenges that face staff in a not-forprofit homeless service provider in the Republic of Ireland called Focus Ireland (FI),in their support of clients who are culturally diverse. The study utilises participant observation and eighteen group interviews (in which fifty-three FI staff members took part) to explore these challenges. In addition, feedback evaluation forms were used in order to examine the effectiveness of an intercultural competence training programme that was designed in response to these issues. This is a timely study, given the significant increase in individuals not originally from Ireland who avail of homeless services. Through the use of Thematic Analysis, a number of themes were identified in relation to the difficulties that staff face in the provision of an effective and appropriate service for customers who are culturally diverse. The findings indicate that they face challenges related to supporting customers in the semi-public and private spheres such as understanding the ways customers seek privacy or the varying childrearing practices customers might employ. Findings also show that FI staff had difficulty supporting families with diverse family structures and the manner in which this impacts on decision-making, power relationships and the nurture of children. Findings also show that staff face the challenge of attempting to combat racist behaviour or discrimination by customers themselves, neighbours and private landlords. The study also found that staff need to develop language competence skills in order to overcome the language barrier they sometimes face, when interacting with customers who speak English as a second or additional language. Analysis of feedback from participants in the second part of the study suggest that a bottom-up ethnographic approach to the design and delivery of a context-specific, intercultural competence training programme is very effective, as many FI staff developed in their level of intercultural competence in terms of knowledge, skills, language competence and attitudes.