To increase public awareness and sensitivity, a two-stage screening with a community-based approach is proposed, with the use of the broadband Taiwan Birth Cohort Study (TBCS) developmental instrument in the first stage and the narrowband Modified Checklist of Autism in Toddlers (M-CHAT) in the second stage. Thus, the purpose of this study was to use the M-CHAT as the lead criteria in the investigation of whether the TBCS developmental instrument can be used in first-stage detection of autism spectrum disorder (ASD) at 6, 18, and 36 months. The TBCS dataset, which included 1783 children in the first stage, 1620 in the second stage, and 1630 in the third stage was used for this study. The M-CHAT and the TBCS 6, 18 and 36 months' developmental scales were collected. Using the M-CHAT, 292 (18.0%) children were screened out as being at high risk for ASD; using this as the lead criteria, the cutoff points of 65/66 for the 6 months' scale, 42/43 for the 18 months' scale and 51/52 for the 36 months' scale, with negative predictive values of 83.44%, 84.21% and 85.35%, respectively, were established. With the cutoff points, TBCS developmental instrument can be used as a community-based first-stage screening instrument at 6, 18, and 36 months. Early diagnosis and intervention optimizes the long-term prognosis of ASD and also decreases family stress. Follow-up of these children and further evaluation using standard diagnostic assessments will help us in understanding the accuracy of the TBCS developmental instrument and M-CHAT use in the community. (Contains 2 tables.)