Background: Aggressive NHLs frequently affect older adults, and are often treated with intensive systemic therapy that is potentially curative but can cause substantial toxicities. Although balancing treatment efficacy with the risk of complications is critically important for older adults with NHL, few studies have described these patients’ survival outcomes, rates of toxicities, and healthcare utilization. Methods: We conducted a retrospective analysis of adults > 65 years diagnosed with aggressive NHL and treated with systemic therapy at Massachusetts General Hospital from 4/2000-7/2020. We abstracted patient demographic and clinical information, survival outcomes, treatment toxicity (rates and grade), and healthcare utilization outcomes (intensive care unit [ICU] admissions and unplanned hospitalizations within six months of treatment initiation) from the electronic health record. Using multivariable logistic regression, we examined patient and disease factors associated with rates of grade 3+ non-hematologic toxicity and unplanned hospitalization. Results: Of 295 patients (median age = 73 years [age 65-69: 32.5%; age 70-74: 26.1%; age 75-79: 20.0%; age 80+: 21.4%], 39.0% female), most had advanced stage disease (59.5%) and an ECOG performance status of 0 or 1 (83.1%). The most common diagnosis was de novo diffuse large B-cell lymphoma (DLBCL) or grade 3B follicular lymphoma (69.2%). Most common therapies were CHOP (65.8%) and EPOCH (17.0%) with or without Rituximab. With a median follow up of 5.9 years, 5-year overall survival (OS) was 74.2%. Among patients age 65-69, 70-74, 75-79, and 80+ years, 5-year OS by age group were 82.1%, 72.2%, 73.5%, and 66.3%, respectively. Overall, 42.4% had grade 3+ toxicity, while 8.1% had grade 4 or 5 toxicity. The rates of unplanned hospitalization and ICU admission during the first 6 months of therapy were 41.0% and 6.1%, respectively. In multivariable analysis, hypoalbuminemia (OR 4.22, 95%, p < 0.001) and number of comorbidities (OR 1.75, p < 0.001) were associated with a greater likelihood of grade 3+ toxicity. Hypoalbuminemia (OR 2.76, p = 0.003), number of comorbidities (OR 1.61, p = 0.001), and receipt of EPOCH (OR 5.41, p = 0.012) were associated with a greater likelihood of unplanned hospitalization. Conclusions: The majority of older adults receiving upfront therapy for aggressive NHL survive beyond 5 years, yet nearly half experience substantial treatment toxicities and unplanned hospitalizations. Our findings underscore the need to develop supportive care interventions to enhance the care experience for older adults with NHL.