Households can minimize residual waste and increase the volume of materials recycled by improving waste separation and changing purchasing behaviour. Informational strategies may provide people information on reasons to minimize waste and information on how to minimize waste. However, a meta-analysis found that the effect of informational strategies on waste minimization is small to medium. While some studies find effects, others do not. To improve the effectiveness of informational strategies to promote waste minimization, it is important to better understand the underlying processes. We proposed and tested if an intervention, consisting of an innovative informational strategy, strengthens the variables from the norm activation model, i.e. increased awareness of consequences, outcome efficacy and personal norms. We conducted a field study in collaboration with a waste collection company. The current study not only tested if the intervention increased the separation of waste, but also whether households changed their purchase behaviour and if they reduced the volume of residual waste. We included self-reported as well as actual behaviour and tested long term effects after the programme ended. Our findings show that the informational strategy effectively reduced households’ waste. Furthermore, the intervention changed waste behaviour partly via the variables from the norm activation model. Particularly, awareness of consequences and outcome efficacy explained the influence of the intervention on waste minimization. Our findings suggest that informational strategies may be effective in minimizing household waste when awareness of consequences and outcomes efficacy are increased by the information.