Ecosystem Services (ES) are critically important to human well-being, and sustaining economic growth and livelihoods. Globally, valuation research has increased markedly over the past two decades, partly due to the influence of environmentalism and the notable depletion of ES. Using meta-analysis of 1156 peer-reviewed journal articles from 1994 to 2017, this study assesses forest ES valuation, focusing on temporal trends, methodological approaches, the types of services most frequently evaluated, and the origin of ES valuation research, especially biomes, economy, and management modalities. Findings suggest that western European countries, including the UK, had the highest number of publications (33%) followed by the United States (15%) and China (13%). Countries with lower middle and low income collectively share only about 14% of the total publications, indicating a large gap in ES research in these countries. In terms of valuation methods, monetary valuation was initially popular, while non-monetary valuation using modelling and mapping methods is gaining popularity. The study revealed that more than 80% of studies have consistently assessed multiple functions of forests but largely focus on regulating services (carbon storage/sequestration/climate regulation). Similarly, about 57% of total ES research was carried out on public land, government managed forests and protected areas, whereas less than 3% was on community-based forestry (CBF), which shares more than 15% and 31% of the forests in developed and developing countries, respectively. Whilst ES publications on forestry have seen significant increases, valuation studies in countries with high biodiversity are conspicuously unrepresented; particularly on forests in mountain regions in low to lower-middle income countries. Some reasons for this disparity in ES research under four themes are discussed, in connection with the global climate change, biodiversity policies, and national, bilateral and multilateral initiatives.