Totally implantable venous access devices (TIVADs) have been widely used for many years in the management of patients suffering from cancer. Thrombotic occlusion is the most common functional complication in the off-treatment period. This study aims to investigate the incidence of and risk factors for TIVADs-related thrombotic occlusion in patients with breast cancer. The clinical data of 1586 eligible patients with breast cancer with TIVADs at the Fourth Affiliated Hospital of Hebei Medical University from 1 January 2019 to 31 August 2021 were analysed. Thrombotic occlusion was confirmed by angiography with signs of partial or total occlusion. Thrombotic occlusion occurred in 96 (6.1%) cases. Multivariable logistic regression analysis showed that the insertion site of the catheter (P = 0.004), size of the catheter (P < 0.001), and indwelling time (P < 0.001) were significant factors for thrombotic occlusion. Insertion in the right internal jugular vein, smaller catheter size and shorter indwelling time can lower the incidence of thrombotic occlusion in breast cancer patients with TIVADs in the off-treatment period.© 2023. The Author(s).