In the article of 1965 Are logical truths analytic? Hintikka deals with the problem of establishing whether the logical truths of first-order logic are analytic or synthetic. In order to provide an answer to this issue, Hintikka firstly distinguishes two different notions of analyticity, and then he shows that the sentences of first-order logic are analytic in one sense, but synthetic in another. This interesting result clearly illustrates the non-triviality of the question. In this paper we aim at answering the question Are modal truths analytic? In order to elaborate a satisfactory answer to this question, we will follow the strategy of Hintikka and we will exploit some recent results on the proof theory for modal logic. Finally, our conclusions will shed new lights on the links between first-order logic and modal logic.