Screen-viewing is one of the most common sedentary behaviors among preschoolers. Despite the high prevalence of sedentary behaviors in childcare, little research exists on the context and/or type of activities that account for these particular behaviors. Accordingly, if the amount of screen-viewing accumulated by preschoolers in childcare is not considered, researchers may be underestimating total screen time among this population, as only a portion of their day is being captured (i.e., the home environment). This systematic review provides a synthesis of research on the levels of screen-viewing among preschool-aged children (2.5-5 years) attending childcare (i.e., centre- and home-based childcare). This review also examined the correlates of screen-viewing among preschoolers in this setting. To provide additional contextual information, availability of screen activities was used to help ameliorate the understanding of preschoolers' screen-viewing behaviors in childcare. Methods: Twelve electronic databases were searched to retrieve relevant articles for inclusion (dating from 2000 onwards). Additional studies were identified via manual searching techniques (i.e., hand searching and citation tracking). Only English, published peer-reviewed articles that examined preschoolers' screen-viewing behaviors in childcare (i.e., rates of screen-viewing and access to/opportunities for related activities) were included. No restrictions to study design were applied. Results: Seventeen international studies (4 experimental; 12 cross-sectional; 1 mixed-methods) published between 2004 and 2014 were examined. Of those, eight studies reported rates of screen-viewing and found that preschoolers spent approximately 0.1 to 1.3 hrs/day and 1.8 to 2.4 hrs/day engaged in this behavior in center- and home-based childcare, respectively. High staff education (negative association) and type of childcare arrangement (notably, home-based childcare in comparison to center-based childcare; positive association) were identified as two correlates in relation to preschoolers' screen-viewing in childcare. Nine studies spoke to the availability of screen-viewing activities in childcare, and found the childcare environment to be conducive to this behavior. Conclusions: Despite some variability, preschoolers appear to engage in somewhat high levels of screen-viewing while in childcare, particularly within home-based facilities. This paper also highlighted the conduciveness of the childcare environment with regard to screen-viewing among preschoolers. Additional exploration into the correlates of screen-viewing in childcare is required. (author abstract)