Background This is the third update of a review that was originally published in the Cochrane Library in 2002, Issue 2. People with cancer, their families and carers have a high prevalence of psychological stress, which may be minimised by e ective communication and support from their attending healthcare professionals (HCPs). Research suggests communication skills do not reliably improve with experience, therefore, considerable e ort is dedicated to courses that may improve communication skills for HCPs involved in cancer care. A variety of communication skills training (CST) courses are in practice. We conducted this review to determine whether CST works and which types of CST, if any, are the most e ective. Objectives To assess whether communication skills training is e ective in changing behaviour of HCPs working in cancer care and in improving HCP well-being, patient health status and satisfaction. Search methods For this update, we searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 4), MEDLINE via Ovid, Embase via Ovid, PsycInfo and CINAHL up to May 2018. In addition, we searched the US National Library of Medicine Clinical Trial Registry and handsearched the reference lists of relevant articles and conference proceedings for additional studies. Selection criteria The original review was a narrative review that included randomised controlled trials (RCTs) and controlled before-and-a er studies. In updated versions, we limited our criteria to RCTs evaluating CST compared with no CST or other CST in HCPs working in cancer care. Primary outcomes were changes in HCP communication skills measured in interactions with real or simulated people with cancer or both, using objective scales. We excluded studies whose focus was communication skills in encounters related to informed consent for research. Data collection and analysis Two review authors independently assessed trials and extracted data to a pre-designed data collection form. We pooled data using the random-e ects method. For continuous data, we used standardised mean di erences (SMDs). Communication skills training for healthcare professionals working with people who have cancer (Review)