Work-related extended availability (WREA; the availability of employees for work-related matters in their leisure time) seems to be associated with decreases in well-being and life-domain balance, but to date there is no quantitative synthesis of the scattered evidence. We conducted a random-effects meta-analysis (113 articles with 121 studies relying on k = 117 independent samples with N = 131,872) on the associations between WREA and employee outcomes while examining potential moderators as well as differences between availability demands and behaviors. WREA was adversely associated with recuperation, well-being and private life, but favorably with some work-related criteria. There were no systematic differences in effect sizes between availability demands and behaviors; however, segmentation preferences were a moderator. Overall, these results suggest that WREA may pose a threat to employee recuperation, well-being and private lives, especially when employees prefer separating work and private life. However, positive potentials of WREA should not be overlooked. Plain Language Summary Work-related extended availability (WREA) refers to the availability of employees for work-related matters in their leisure time. Studies have shown that WREA may go along with primarily negative consequences for employees, but to date, there is no comprehensive overview of the literature statistically summarizing the current state of research, which was done in the study at hand. We assumed that WREA be related to problems with recovery, poorer well-being and difficulties to find a balance between work and private life. We also assessed in how far WREA goes along with attitudes towards work, absence from work and the intention to change jobs. Moreover, we considered differences between demands to be available and behaviors of actually taking care of work-related matters during leisure time. Finally, we investigated factors that may be associated with stronger consequences of WREA. We included 113 scientific papers with a total of 131,872 participants. WREA was related to problems with recovery, poorer well-being and difficulties to find a balance between work and private life, but also to more positive attitudes towards work. We did not find systematic differences between demands to be available and availability behaviors. However, we found that the relationship between WREA and work creating conflict with family life were stronger in samples with higher preferences to segment work and private life. Our findings suggest that WREA may pose a threat to employee recuperation, well-being and private lives, especially when employees prefer separating life domains. Still, positive potentials of WREA should not be overlooked.