We examine the relationship between women's age at marriage and their labour market outcomes using nationally representative household data from India. Employing an instrumental variable-based empirical strategy, we find that a delay in women's age at marriage has no significant causal effect on their labour market outcomes. This is despite marriage delay being associated with higher education, lower fertility and (possibly) higher dowry for Indian women. We argue that this might be because older brides, as compared with younger brides, face more backlash from their partners. This backlash effect could be offsetting the positive labour market effects of marriage delay. extcopyright 2020 John Wiley & Sons, Ltd.