DNA replication and sister chromatid cohesion 1 (DSCC1) exerts various functions including sister chromatid cohesion. DSCC1 overexpression plays an important role in cancer development, such as in colorectal, breast, and hepatocellular cancers. The specific role of DSCC1 in tumor progression remains largely unknown, necessitating a pan-cancer investigation to understand the potential function of DSCC1 in various cancers. In this study, we obtained data on physiological conditions, transcriptional expression, survival prognosis, genomic alteration, genomic instability, enriched pathways, immune infiltration, and immunotherapy from The Cancer Genome Atlas, The Genotype-Tissue Expression, cBioPortal, and other publicly available databases to systematically characterize the oncogenic and immunological roles of DSCC1 in 33 different cancers. We found that DSCC1 expression was upregulated at both mRNA and protein levels in various cancers. Additionally, DSCC1 expression was associated with higher tumor stage and grade in specific cancers. DSCC1 was a potential pan-cancer prognostic biomarker for its close association with patient prognosis and a diagnostic biomarker for its high predictive value in distinguishing tumor tissues from normal tissues. DSCC1 was universally amplified across different cancers and tightly associated with genomic instability. Moreover, DSCC1 had a close relationship with tumor immune cell infiltration; thus, it could be used as a potential biomarker for predicting the response and survival of patients with cancer who receive immune checkpoint blockade treatment. To sum up, our study revealed that DSCC1 is a promising target for tumor therapy.