The justifiability scale (JS) is widely used to measure individual and country differences in moral attitudes. However, the validity of the instrument has been barely assessed. The current study addressed the concurrent and content validity of four popular JS items (justifiability of homosexuality, suicide, prostitution, and euthanasia). A sample of 493 Russians completed both JS and the four validated multi-item scales. Results demonstrated that multi-item scales measuring suicide, prostitution, and euthanasia attitudes explained less than half of the variance of the corresponding JS items. The JS underestimated the justifiability of homosexuality, prostitution and suicide, and overestimated the justifiability of euthanasia. The JS homosexuality item appeared to be a precise measure of attitudes towards male but less so female homosexuality. The concurrent validity of the four items was associated with item non-differentiation. We conclude that JS items should be used either after accounting for their bias, or as indicators of more abstract latent constructs.