It is common for jurisdictions tasked with minimising gambling-related harm to conduct problem gambling prevalence studies for the purpose of monitoring the impact of gambling on the community. However, given that both public health theory and empirical findings suggest that harms can occur without individuals satisfying clinical criteria of addiction, there is a recognized conceptual disconnect between the prevalence of clinical problem gamblers, and aggregate harm to the community. Starting with an initial item pool of 72 specific harms caused by problematic gambling, our aim was to develop a short gambling harms scale (SGHS) to screen for the presence and degree of harm caused by gambling. An Internet panel of 1524 individuals who had gambled in the last year completed a 72-item checklist, along with the Personal Wellbeing Index, the PGSI, and other measures. We selected 10 items for the SGHS, with the goals of maximising sensitivity and construct coverage. Psychometric analysis suggests very strong reliability, homogeneity and unidimensionality. Non-zero responses on the SGHS were associated with a large decrease in personal wellbeing, with wellbeing decreasing linearly with the number of harms indicated. We conclude that weighted SGHS scores can be aggregated at the population level to yield a sensitive and valid measure of gambling harm.