Clustered robust meta-regression analysis is applied to 109 willingness to pay (WTP) estimates for threatened species from 47 stated-preference studies in 19 countries. Our study updates previous meta-analyses on the topic and tests the effect of important variables not previously considered—species' threat status, use of coloured photographs of species in a survey, and a country's development status, on WTP. We also compared model results obtained from weighting observations by the inverse standard error of WTP and inverse sample size values. Inverse-standard error-weighted model results were more aligned with published research and economic theory and had a better fit than inverse-sample size-weighted model results. Average total present value of WTP was