Background Evidence about the association of high blood eosinophil count with asthma exacerbation is inconsistent and unclear. The objective of this meta‐analysis was to determine whether elevated blood eosinophil count predicts asthma exacerbation. Methods We searched MEDLINE, EMBASE, and additional databases, without any language restriction. We also checked the reference lists of the included studies and of relevant systematic reviews. The main outcome was the occurrence of asthma exacerbation. We calculated global pooled odds ratios (ORs) and their 95% confidence intervals (CIs) and performed predefined subgroup analyses. We appraised the quality of the studies using Newcastle‐Ottawa Scale, examined the heterogeneity between studies, assessed publication bias, and carried out sensitivity analyses. Results Among 1567 retrieved publications, 23 observational studies comprising 155,772 participants met the inclusion criteria. High blood eosinophil count was associated with higher odds of asthma exacerbation OR: 1.31 (95% CI: 1.16, 1.49), specifically with asthma‐related outpatient visits OR: 1.46 (95% CI: 1.25, 1.70) and emergency department visits OR: 1.63 (95% CI: 1.29, 2.07). A significant association was observed starting from an eosinophils’ cutoff value of 200 cells/μl. The association was observed for cohort studies OR: 1.30 (95%CI: 1.13, 1.49), North American studies OR: 1.43 (95%CI: 1.31, 1.57), Asian populations OR: 1.67 (95%CI: 1.34, 2.08), children OR: 1.38 (95%CI: 1.22, 1.56), and studies that adjusted for inhaled corticosteroids therapy OR: 1.42 (95%CI: 1.28, 1.56). Conclusions Blood eosinophil counts ≥ 200 cells/µL are associated with asthma exacerbation. Blood eosinophil count is a modifiable factor that could be addressed in asthma management strategies.