The last Sura that was revealed was Bara'a, and the last Verse that was revealed was: "They ask you for a legal verdict, Say: Allah's directs (thus) about those who leave no descendants or ascendants as heirs." (4.176)  

آخِرُ سُورَةٍ نَزَلَتْ بَرَاءَةَ وَآخِرُ آيَةٍ نَزَلَتْ {يَسْتَفْتُونَكَ }