Economic values of biological collections in three Australian botanic gardens in Canberra, Melbourne and Sydney were estimated using the travel-cost method (TCM) and the contingent valuation method (CVM). The TCM component of the study produced average per-trip consumer surplus (CS) values of $39 and $18 for single- and multiplesite visitors, respectively, for each botanic garden, resulting in an estimate of approximately $194 million for the total social welfare generated by trips to the three sites. Marginal willingness to pay (WTP) for access to botanic gardens was also investigated through payment vehicles of entry fees or higher parking charges using the CVM component. The analysis revealed a positive mean WTP of between $3 and $5 per trip per person. The difference between the CVM and TCM results reflect the different underlying concepts of value under investigation: average CS per visit for the TCM and the utility arising from a marginal visit for the CVM. Marginal changes in CS from the TCM were derived. The confidence intervals from the TCM marginal values overlap the WTP estimates from the CVM. These findings will be useful for resource management decisions in the botanic gardens collection in Australia.