To cite this version:Athanassios Koutsonas, Dimitrios M. Thilikos, Koichi Yamazaki. Outerplanar obstructions for matroid pathwidth. Discrete Mathematics, Elsevier, 2014, 315, pp.95-101 For each non-negative integer k, we provide all outerplanar obstructions for the class of graphs whose cycle matroid has pathwidth at most k. Our proof combines a decomposition lemma for proving lower bounds on matroid pathwidth and a relation between matroid pathwidth and linear width. Our results imply the existence of a linear algorithm that, given an outerplanar graph, outputs its matroid pathwidth.