Lateral flow immunochromatographic strip tests (IST) are very promising for use as on-site test diagnostic tools in developing countries. In this work, a fabrication process simplified, lateral flow immunochromatographic test strip for aflatoxin M₁ (AFM₁) detection in milk samples has been developed. The immunostrip was specific to AFM₁ showing no cross-reactivity with other major aflatoxins. The visual detection limit (VDL) and threshold level for AFM₁ was 0.3 and 4.0 ng mL⁻¹, respectively. Evaluation results of the IST revealed good accuracy and repeatability. In the detection of AFM₁ contamination level in milk samples, visual results of the IST are in good correlation with those of a quantitative enzyme-linked immunosorbent assay (ELISA). This AFM₁–IST, employing a one-step method, was environmentally friendly without the use of any organic reagents or buffers and additional equipment, and could serve as an on-site and home-use device for AFM₁ tests in milk, and be helpful to people's health care.