Although nanoliposomal irinotecan combined with 5-fluorouracil and leucovorin (nal-IRI+5-FU/LV) has been used to treat first-line resistant unresectable pancreatic cancer, the efficacy and safety data among the elderly remain limited. We retrospectively analyzed clinical outcomes among elderly patients. Patients treated with nal-IRI+5-FU/LV were assigned to the elderly (≥75 years) and non-elderly (<75 years) groups. Herein, 85 patients received nal-IRI+5-FU/LV, with 32 assigned to the elderly group. Patient characteristics in the elderly and non-elderly groups were as follows: age: 78.5 (75–88)/71 (48–74), male: 17/32 (53%/60%), performance status (ECOG) 0:9/20 (28%/38%), nal-IRI+5-FU/LV in second line: 23/24 (72%/45%), respectively. A significantly high number of elderly patients exhibited aggravated kidney and hepatic functions. Median overall survival (OS) and progression-free survival (PFS) in the elderly group vs. non-elderly group were 9.4 months vs. 9.9 months (hazard ratio (HR) 1.51, 95% confidence interval (CI) 0.85–2.67, p = 0.16) and 3.4 months vs. 3.7 months (HR 1.41, 95% CI 0.86–2.32, p = 0.17). Both groups exhibited a similar incidence of efficacy and adverse events. There were no significant differences in OS and PFS between groups. We analyzed the C-reactive protein/albumin ratio (CAR) and neutrophil/lymphocyte ratio (NLR) as indicators that could determine eligibility for nal-IRI+5-FU/LV. The median CAR and NLR scores in the ineligible group were 1.17 and 4.23 (p < 0.001 and p = 0.018, respectively). Elderly patients with worse CAR and NLR score could be deemed ineligible for nal-IRI+5-FU/LV.