Aims To develop a gold immunochromatographic test strip for on-site rapid detection of lymphocystis disease virus (LCDV). Methods and Results Monodispersional colloidal gold and gold-labelled anti-LCDV monoclonal antibody (McAb) 2D11 were prepared and characterized by UV-visible spectroscopy and transmission electron microscopy. Gold-labelled probe was used as the detection antibody, and goat anti-mouse IgG at the control line and anti-LCDV McAb 1A8 at the test line of the test strip served as the capture antibody. The positive results could be easily judged by the presence of a red test line with naked eye within 10 min. The test strip, in good agreement with enzyme-linked immunosorbent assay and dot-blotting in sensitivity and LCDV detection, gave a detection limit of 1 mu g ml-1 of LCDV and was stable for 6 months at room temperature and 12 months at 4 degrees C. Conclusions The test strip was specific, simple and convenient for rapid detection of LCDV presenting good stability and reproducibility. Significance and Impact of the Study This ready-to-use test strip allows on-site rapid detection of LCDV in fish without the requirement of specialized equipments and professional personnel, which could augment the practical application for diagnosis of LCDV even in disadvantage areas.