The international response to civil conflicts has sometimes been to intervene in situations of extreme human rights abuses with the alleged purpose of stopping the continuation of the violence. This became known as humanitarian intervention and its study has mainly focused on when are these likely to take place and under what conditions are they likely to be effective. However, no conclusive answer has been provided. This is partly due to the fact that the two issues at stake, that is, the when and how, have remained largely separately assessed, missing the opportunity to find out what, if any, is the relationship between the motives that lead a state to intervene and the intervention''s outcome. If there is a relationship between motives and outcomes, then the study of humanitarian intervention would benefit from knowing what type of relationship this is, as it would bring clarity to the issue of when a humanitarian intervention is more likely to be effective. This work examines this relationship by asking what types of motives are more likely to produce successful outcomes in humanitarian interventions and uses the cases of Guatemala and East Timor to answer that question.