Comorbidities are associated with adverse patient outcomes. The authors conducted a systematic review according to a pre-determined protocol, established PRISMA guidelines and reporting standards to estimate the prevalence of common comorbidities in people with epilepsy, and to explore whether the burden is greater in more deprived populations. In total, 107 studies were included and reviewed. The results indicate that the most common comorbidities in people with epilepsy are anxiety (19.2%) and major depressive disorder (17.4%). Among adults with epilepsy, common comorbidities include hypertension (18.2%), stroke (14.5%), heart disease (11%), diabetes (10.2%) and arthritis (9.2%). There was no evidence that the income status of a country was a moderating factor for the prevalence of anxiety and depression in people with epilepsy. However, prevalence rates for hypertension and stroke were lower for lower-income countries where epilepsy is a more common symptom of brain infection or injury. The analyses were affected by the heterogeneity of the included studies and should therefore be interpreted cautiously.