IntroductionThe availability of low-cost computing and digital telecommunication in the 1980s made telehealth practicable. Telehealth has the capacity to improve healthcare access and outcomes for patients while reducing healthcare costs across a wide range of health conditions and situations.ObjectiveThis study compares the adoption, advantages, and challenges of telehealth services between high-income (HICs) and low-and-middle-income countries (LMICs) before and during the COVID-19 pandemic.MethodsPreferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The key search terms were: “Telehealth”, “Telehealth in HICs”, “Telehealth in LMICs”, “Telehealth before COVID-19”, “Telehealth during COVID-19”. We searched exhaustively ProQuest, Scopus, Web of Science, Google Scholar, CINAHL, and EMBASE databases from 2012. Booleans OR/AND were combined with key search terms to increase relevant search results. The literature search and selection process followed the Sample, Phenomena of Interest, Design, Evaluation, and Research (SPIDER) question format.ResultsThe adoption of telehealth before COVID-19 was generally low in both HICs and LMICs. The impact of COVID-19 accelerated the adoption of telehealth at the facility level but not nationwide in both high-income countries and LMICs. The rapid adoption of telehealth at the facility level in both high-income and LMICs introduced several challenges that are unique to each country and need to be addressed.ConclusionThe lack of national policies and regulations is making the adoption of telehealth at the national level challenging in both high and low-middle-income countries. Governments and Stakeholders of healthcare must consider telehealth as a healthcare procedure that should be deployed in clinical working procedures. Primary quantitative and qualitative studies must be conducted to address challenges encountered during the pilot implementation of telehealth services in both high-income countries and LMICs before and during pandemics.