Background <p>Narrow-spectrum antimicrobials are likely to drive fewer antimicrobial resistances. However, they may be more expensive than broad-spectrum alternatives.</p> Objective <p>To determine the preferences of antimicrobial stewardship (AMS) experts regarding antimicrobial choice relative to relevant pharmacological and economic attributes, and how those attributes impact their willingness-to-pay for narrow-spectrum of activity.</p> Methods <p>Two discrete choice experiments (DCEs), consisting of six pharmacological and economic attributes, were administered via an online survey to Australian infectious disease physicians, clinical microbiologists and hospital AMS pharmacists. Respondents were asked to complete each DCE from a public hospital perspective, assuming 100 or 1000 patients would be treated each year, respectively. A conditional logit model was used to analyse the DCE data.</p> Results <p>155 respondents participated in one or both DCEs. Antimicrobial price, spectrum of activity, administration route, and public funding significantly affected drug choice in both scenarios (<i>p</i> &lt; 0.001). Whether the antimicrobial was a novel class did not significantly impact choice. As the price of a narrow-spectrum antimicrobial increased, it became less preferred compared to a broad-spectrum cheaper alternative. With all other attributes being equal, participants were willing to pay an additional AU$862 for the narrow-spectrum option (95% CI $726–$998).</p> Conclusions <p>While narrow-spectrum antimicrobials are preferred for targeted therapy by health practitioners with AMS expertise, price significantly influenced drug choice. Willingness-to-pay values reflect the knowledge and experience of AMS experts who are best-placed to gauge the opportunity costs of paying more for narrow-spectrum antimicrobials. These findings can inform the quantification of spectrum-value for health-system funding decisions.</p>