Crude secondary attack rate (SAR) of COVID-19 in Taiwan was 0.84% using nationwide contact-tracing data till April 8, 2020. The random-effect Bayesian metaanalysis yielded 95% credible intervals of 0.42%-1.69% and 0.08%-8.32%, respectively, for estimated SAR pooling from 15 case series and for predicted SAR in the future if pandemic continues.