Abstract Background Hospitalisation resulting from complications of systemic therapy and radiotherapy places a substantial burden on the patient, society, and healthcare system. To formulate preventive strategies and enhance patient care, it is crucial to understand the connection between complications and the need for subsequent hospitalisation. This review aimed to assess the existing literature on complications related to systemic and radiotherapy treatments for cancer, and their impact on hospitalisation rates. Methods Data was obtained via electronic searches of the PubMed, Scopus, Embase and Google Scholar online databases to select relevant peer-reviewed papers for studies published between January 1, 2000, and August 30, 2023. We searched for a combination of keywords in electronic databases and used a standard form to extract data from each article. The initial specific interest was to categorise the articles based on the aspects explored, especially complications due to systemic and radiotherapy and their impact on hospitalisation. The second interest was to examine the methodological quality of studies to accommodate the inherent heterogeneity. The study protocol was registered with PROSPERO (CRD42023462532). Findings Of 3289 potential articles 25 were selected for inclusion with ~ 34 million patients. Among the selected articles 21 were cohort studies, three were randomised control trials (RCTs) and one study was cross-sectional design. Out of the 25 studies, 6 studies reported ≥ 10 complications, while 7 studies reported complications ranging from 6 to 10. Three studies reported on a single complication, 5 studies reported at least two complications but fewer than six, and 3 studies reported higher numbers of complications (≥ 15) compared with other selected studies. Among the reported complications, neutropenia, cardiac complications, vomiting, fever, and kidney/renal injury were the top-most. The severity of post-therapy complications varied depending on the type of therapy. Studies indicated that patients treated with combination therapy had a higher number of post-therapy complications across the selected studies. Twenty studies (80%) reported the overall rate of hospitalisation among patients. Seven studies revealed a hospitalisation rate of over 50% among cancer patients who had at least one complication. Furthermore, two studies reported a high hospitalisation rate (> 90%) attributed to therapy-repeated complications. Conclusion The burden of post-therapy complications is emerging across treatment modalities. Combination therapy is particularly associated with a higher number of post-therapy complications. Ongoing research and treatment strategies are imperative for mitigating the complications of cancer therapies and treatment procedures. Concurrently, healthcare reforms and enhancement are essential to address the elevated hospitalisation rates resulting from treatment-related complications in cancer patients.