Microfracture surface structure of segmented polyurethanes (PUs) with different chemical and physical structures was tested in manually broken samples far below their glass transition. To observe the microfracture surface, transmission electron microscopy (TEM) was utilized. Some correlations between swelling degree (thus physical structure) and the appearance of the microfracture surface pattern were found in chemically different PUs. A radial microfracture topology was observed for cross-linked PU networks.