Women outnumber men in assisted living (AL). This gender imbalance promotes the feminization of AL settings and affects men’s social experiences, particularly their co-resident relationships. AL research connects peer relationships to resident well-being and suggests gender that influences co-resident interactions. Yet, few studies have specifically examined men’s social experiences in AL. This analysis aimed to: (1) learn how men experience co-resident relationships in AL; and (2) identify the factors shaping these peer relationships. The analysis utilized qualitative data collected from two AL settings. Data collection involved participant observation and informal and formal in-depth interviews. Analysis was informed by principles of Grounded Theory Method and shows high variability in men’s co-resident connections. A range of individual- and facility-level factors promoted or constrained relationship development. Gender remains pivotal in structuring men’s social engagements. Individual- and facility-level factors often intersected with gender and influenced men’s social lives. Ultimately, co-resident relationships are consequential for men in AL.