A neural network has been used to predict both the location and the type of β-turns in a set of 300 nonhomologous protein domains. A substantial improvement in prediction accuracy compared with previous methods has been achieved by incorporating secondary structure information in the input data. The total percentage of residues correctly classified as β-turn or not-β-turn is around 75% with predicted secondary structure information. More significantly, the method gives a Matthews correlation coefficient (MCC) of around 0.35, compared with a typical MCC of around 0.20 using other β-turn prediction methods. Our method also distinguishes the two most numerous and well-defined types of β-turn, types I and II, with a significant level of accuracy (MCCs 0.22 and 0.26, respectively).