Variations in the untranslated regions (UTRs) of messenger RNAs (mRNAs) impact post-transcriptional regulation and thereby RNA fate. Alternative splicing of 3’UTRs is widespread, upregulated in most cancers, and drives tumorigenesis. However, the prevalence and role of 3’UTR splicing in gastric cancer (GC) development and treatment response have not been comprehensively characterized. Here, we integrated PacBio long-read isoform sequencing (Iso-Seq) data from 10 GC cell lines and short-read RNA sequencing data from The Cancer Genome Atlas (TCGA), and identified 902 3’UTR splicing events (3USPs). Quantifying and comparing the splicing levels (SPLs) of each 3USP in tumors with their adjacent normal in TCGA-STAD revealed significant differences in 93 events (32 up and 61 down-spliced). Kaplan–Meier analysis showed that 30 events were significantly correlated with overall survival. In summary, our study shows the landscape of 3’UTR splicing and investigates its impact on gastric cancer progression. Our results suggest that 3USPs could be potential prognostic markers for GC progression and may contribute to GC tumorigenesis. Molecular studies are currently in progress to validate and functionally characterize these dysregulated 3USPs and elucidate the underlying mechanisms by which these 3USPs contribute to gastric tumorigenesis.