High robustness of complex ecological systems in the face of species extinction has been hypothesizedbased on the redundancy in species. We explored how differences in network topology may affect robustness.Ecological bipartite networks used to be small, asymmetric and sparse matrices. We created syntheticnetworks to study the influence of the properties of network dimensions asymmetry, connectance andtype of degree distribution on network robustness. We used twoextinction strategies: node extinction and link extinction,and three extinction sequences differing in the order of species removal (least-to-mostconnected, random, most-to-least connected).We assessed robustness to extinction of simulated networks, which differed in oneof the three topological features. Simulated networks indicated that robustness decreaseswhen (a) extinction involved those nodes belonging to the most species-rich guild and (b)networks had lower connectance. We also compared simulated networks with different degree-distribution networks, and they showed important differences in robustness depending on the extinctionscenario. In the link extinction strategy, the robustness of synthetic networks was clearly determined bythe asymmetry in the network dimensions, while the variation in connectance produced negligibledifferences.