Mobilephone distraction in learning is a widely observed phenomenon due to dividing and switching attention between learning activities (e.g., attending lectures and reading textbooks) and off-task activities (e.g., texting and chatting). In the past 30 years, hundreds of empirical studies have examined this distraction and generated abundant but inconclusive findings. Built on two influential meta-analyses (Liu et al., 2017; Kates et al., 2018), this meta-analysis aimed to systematically synthesize evidence from 27 randomized controlled experiments, with a total of 55 effect sizes and 2245 participants, and precisely estimate the effect of mobilephone distraction on students' immediate recall scores for the first time. It is concluded that mobilephone distraction (1) causes an overall negative medium-sized effect on immediate recall (Hedges'g = −0.65, 95% CI [-0.81, −0.49]), (2) has a negative nearly-large-sized effect on lecture recall (Hedges's g = −0.70, 95% CI [-.86, -.54]), (3) is significantly moderated by gender but not by the 10 other moderators related to study features and demographical variables, and (4) is not distorted by publication bias, outlier studies, and missing data. These findings and future studies are discussed.