Trastuzumab has been the standard treatment in first-line treatment of HER-2-positive advanced breast cancer (H2ABC). This study explored whether the delayed and repeated use of trastuzumab could influence overall survival (OS). A total of 128 patients with H2ABC who had received at least one line of trastuzumab-based regimens were included. The primary endpoint was OS defined as from the date of first diagnosis of H2ABC to death. The median OS of initiating trastuzumab in first-line group (n = 56), in the second-line group (n = 32), and the third- or more-line group (n = 40) was 40.6 m, 39.5 m, and 38 m, respectively (P = 0.867). For patients who had received over one line of trastuzumab (n = 46), the median OS was 44 m, and for those receiving only one line (n = 67), it was 27.6 m (P = 0.059). The delayed use of trastuzumab has no negative effect on the OS of patients with H2ABC. There is a trend of improved OS over the repeated use of trastuzumab.