Background: Physician dual practices (PDP) is a term used to describe physicians who combine work in public and private health-care sector. This study aimed to find evidence of PDP worldwide, investigate its reasons and consequences, and compare high-income (HIC) versus low and middle-income countries (LMIC). Methods: In this literature review, the search for PDP evidence was conducted in the English language. PubMed and Google were searched for relevant publications up to Sep 30, 2020. Results: Of 195 countries, PDP-reports were found in 157 countries (81%). No significant difference in prevalence of PDP was found between HIC (77%) and LMIC (82%). Most common reason for working in private sector was low government salaries in public hospitals (55%). This was more reported in LMIC (65%) than HIC (30%; P<0.001). Most common reason for working in public sector was patient recruitment for private practice (25%). This was more reported in HIC (45%) than LMIC (16%; P<0.001). PDP were described as detrimental to public health-sector in 58% of country-reports. Most common adverse consequence was lower quality-of-care in public hospitals (27%). LMIC with PDP-reports had more severe corruption (P<0.001), lower current health-expenditure (P<0.001), and higher out-of-pocket expenditure (P<0.001) than HIC. Scale of PDP was common in more LMIC (92%) than HIC (60%; P<0.001). Government policies to address PDP did not differ significantly between HIC and LMIC. Conclusion: PDP were present in most HIC and LMIC. In majority of reports a detrimental effect of PDP on public health-care was described.