Social interaction is thought to be important for psychological wellbeing and is necessary for developing relationships between older adults living in facilities. This study seeks to describe the social interaction that occurs amongst tablemates at mealtime in retirement homes, as well those things that influence resident-to-resident interaction. Fourteen lunch time periods were the basis for qualitative participant observation. Two or three researchers collected data in each period, with each observing two tables, resulting in 63 individual table observations at a retirement living facility dining room in a medium-sized city in Southern Ontario. Residents attending mealtime in the dining room were (~ 100). The type, extent and influences on social interactions amongst tablemates were recorded in detailed field notes. Qualitative thematic analysis, using a constant comparison procedure, was used to summarize and make sense of the data. A variety of social interactions occurred amongst tablemates including: making conversation, providing assistance, sharing, humouring, showing appreciation and affection, and rebuffing/ignoring/excluding. Interactions were influenced by tablemate roles, resident characteristics, and the social and physical environment, including staff. Social interactions or lack thereof are important for relationship development and mealtime environment. Describing the types of interaction and what influences them is a first step towards promoting social engagement which can enhance quality of life for residents. Further investigation through interviews with residents on the meaning of mealtime and companionship at meals will build a deeper understanding of the importance and influences on social interaction in this setting.