The Denver Developmental Screening Test, Singapore (DDST, Singapore), a Singapore version of the Denver II Developmental Screening Test, was field-tested, using trained staff nurses as testers, on 2459 children (known cases excluded), in 5 key ages of 3 months, 9 months, 17 months, 37 months and 60 months. Only 2.6% (65) of the parents suspected developmental problems in their children before screening. Taking children with "questionable" (7.2%), "abnormal" (3.7%) and "untestable" (1.7%) scores as the screened-out cases, the DDST, Singapore had a screened-out rate of 12.6%. A total of 171 screened-out cases and 168 "normal" children were also evaluated by the Development Assessment Clinic (DAC) of the Singapore General Hospital and the results were compared in these 2 groups of children. Among the screened-out cases, 16.6% were confirmed or suspected to have neuro-developmental disorders (NDDs) by the DAC. The computed NDD rate in the study sample was 5.3%. Based on a single DDST, Singapore test result, there was a high false positive rate of 83.5% and lower false negative rate of 3.7% compared to the DAC assessment. However, the high false positive rate would be significantly reduced by doing a repeat screening test on the "questionable" cases and having the screened-out cases assessed by trained primary health care doctors. In conclusion, no major revision is needed in the scoring criteria suggested in the current version of DDST, Singapore. It is a useful tool in identifying children who will otherwise be missed without formal screening.