Right heart thrombus in transit or “free-floating right heart thrombus” is defined as thrombus(i) arising from the deep veins that embolises to the right atrium or right ventricle before reaching the pulmonary vasculature. It is almost always associated with pulmonary thromboembolism and is a medical emergency with reported mortality rates of over 40%. We present two cases of right heart thrombus in transit with pulmonary thromboembolism resulting from venous thrombosis associated with peripherally inserted central catheters that were managed with different approaches. The cases highlight that clinicians should have a low threshold to utilise imaging modalities such as computerised tomography and transthoracic echocardiography when there is an untoward change in physiological parameters among patients with peripherally inserted central catheters, particularly those with risk factors for peripherally inserted central catheter associated venous thrombosis. Furthermore, procedural optimisation surrounding peripherally inserted central catheters, such as insertion technique and choice of lumen size, is underscored.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12959-023-00513-3.