Hola Folks! I finally gave up the try using BGL, well, for the moment anyway. I'll latter look into the matter a gain. For now, this is my approach (I know this is really an over kill, but I just want things to work first) 1.) find all combinations of at least 3 vertices (my graphs are not big, max 45 vertices so far) 2.) remove all repeating permutations e.g. for A-B-C-A = B-C-A-B = C-A-B-C, use regex to match and select only one such cycle since they are all thesame in an undirected graph. 3.) For each set from 2.) above, check its connectivity and accept if it has a single cycle i.e number of vertices = number of edges Done! -- View this message in context: http://boost.2283326.n4.nabble.com/Identify-cycles-in-a-undirected-graph-tp4... Sent from the Boost - Users mailing list archive at Nabble.com.