People living with HIV (PLHIV) are more likely than the general population to develop AIDS-defining malignancies (ADMs) and several non-ADMs (NADMs). Information is lacking on survival outcomes and cause-specific mortality after cancer diagnosis among PLHIV. We investigated causes of death within 5 years of cancer diagnosis in PLHIV enrolled in European and North American HIV cohorts starting antiretroviral therapy (ART) 1996-2015, aged ≥16 years, and subsequently diagnosed with cancer. Cancers were grouped: ADMs, viral NADMs and nonviral NADMs. We calculated cause-specific mortality rates (MR) after diagnosis of specific cancers and compared 5-year survival with the UK and France general populations. Among 83,856 PLHIV there were 4,436 cancer diagnoses. Of 603 deaths after ADM diagnosis, 292 (48%) were due to an ADM. There were 467/847 (55%) and 74/189 (39%) deaths that were due to an NADM after nonviral and viral NADM diagnoses, respectively. MR were higher for diagnoses between 1996 and 2005 versus 2006-2015: ADMs 102 (95% CI 92-113) per 1,000 years versus 88 (78-100), viral NADMs 134 (106-169) versus 111 (93-133) and nonviral NADMs 264 (232-300) versus 226 (206-248). Estimated 5-year survival for PLHIV diagnosed with liver (29% [19-39%]), lung (18% [13-23%]) and cervical (75% [63-84%]) cancer was similar to general populations. Survival after Hodgkin's lymphoma diagnosis was lower in PLHIV (75% [67-81%]). Among ART-treated PLHIV diagnosed with cancer, MR and causes of death varied by cancer type, with mortality highest for liver and lung cancers. Deaths within 5 years of NADM diagnoses were more likely to be from cancer than AIDS.