I've been involved in a few discussion on iteration length lately and was going to write something about it, but it turns out I don't really have to... Since it would more or less be a repetition of this. So sorry, there will not be a list of five reasons to shorten your iterations here... But I would like to add one thing. Scrum is not a silver bullet. Scrum helps getting surfacing problems and if you think the length of the sprint makes something cumbersome you should shorten the sprint because the more it hurts, the more likely you are to address the real problem and fix it. Souse this rule of thumb (not only for sprint length): If it hurts, make it hurt some more. That way you have a good incentive to fix it.