(1) Background: The purpose of this study was to evaluate the time toxicity, or time spent in health care, of immunotherapy- versus chemotherapy-based regimens for metastatic esophageal and gastric cancers. (2) Methods: A literature search was conducted, and 18 phase III clinical trials of immune checkpoint inhibitors were selected for analysis. Health care days were calculated based on the number of days associated with receiving therapy and the adverse events reported in the clinical trials. Both the number of health care days and the median overall survival were compared among chemotherapy-only, immunotherapy-only, and chemo-immunotherapy regimens across this cohort of drug registration trials. (3) Results: The estimated median number of health care days was 37 (range of 7-52) days, or 1.2 (range of 0.2-1.7) months, compared to a median survival of 10.2 months across these 18 studies. For the chemotherapy-only regimens, the median number of health care days was 39 (range of 21-51) days, and for chemo-immunotherapy, it was 39 (range of 30-52) days. The immunotherapy-only regimens had fewer days, a median of 28 (range of 24-41), < 0.05, compared to the other two arms. (4) Conclusions: The chemo-immunotherapy regimens did not add time toxicity compared to chemotherapy alone. The immunotherapy-only regimens had lower time toxicity compared to chemotherapy alone. In the setting of decreased time toxicity and improved overall survival, further development of immunotherapy-based regimens could improve outcomes in advanced esophageal and gastric cancers.