The Harm Reduction Acceptability Scale (Goddard, 2003) is one of the few published measures of attitudes toward harm reduction, but it no longer reflects the contemporary scope of harm reduction practices. We created a revised 25-item scale, the HRAS-2, reducing stigmatizing language and adding items about newer harm reduction practices such as safer supply. Using three participant samples (total N: 1220), we provide multiple indices supporting the reliability and validity of the HRAS-2. The scale has high internal consistency and test-retest reliability. Convergent validity evidence comes the scale's significant negative correlations with measures of stigmatizing attitudes toward people who use drugs and political conservatism. Additional validity evidence is clear from the HRAS-2's ability to detect changes in attitudes following harm reduction education and its ability to discriminate between people with low versus high levels of information about harm reduction.