The aim of the overview was to synthesize existing systematic reviews (SRs) of flushing interval for patients who inserted totally implanted venous catheter devices (TIVAD). Regular flushing is indispensable for catheter patency, the recommended flushing interval of TIVAD is 4 weeks, however, there is an argument for prolonging the maintenance interval, which has been proved by many SRs. However, the flushing interval range from 4-week to 3-month. The discrepancy in maintenance period could puzzle health professionals and hinder best practice into the clinic. So, we performed the overview by following the PRISMA statement. The PubMed, Ovid, Wan Fang database, Web of Science, CINAHL, CNKI, EMBASE, Cochrane Library were searched from inception to November 2021. The AMSTAR-2, the PRISMA statement, and ROBIS tool were used to assess SRs’ method, report quality, and risk of bias, respectively. Then all results were synthesized, the quality of SRs' results was evaluated with GRADE. Finally, five SRs were included. However, non-randomized and small sample size of original studies result in the limitation of SRs. The evidence grade of conclusions is low, bias of mixed factors in included studies, further large sample sizes, RCTs need to be conducted in the future. Prolonged flushing interval was feasible based on the recent evidence, especially during the COVID-19 pandemic because the overwhelming healthcare system and inconvenience of transportation made maintenance not as easy as it used to be. There is no difference of complication between prolonged flushing interval (⩾4-week) and 4-week period, and it can also reduce healthcare cost with no harm to patients.