The aim of this prospective follow-up study was to evaluate the accuracy of a parent-completed questionnaire compared with professionally detected developmental delay. Parents of 108 very-low-birthweight (VLBW) infants and parents of 279 term control infants completed the German version of the Revised Prescreening Developmental Questionnaire (R-PDQ) at the corrected age of 12 months. Simultaneously, infants underwent developmental examination using the Griffiths Developmental Scale. Sixty-nine VLBW infants were classified as not delayed, 16 as delayed by both methods (conegativity 76% and copositivity 94%), as compared to 240 and six term control infants (conegativity 88%, copositivity 94%). The questionnaire suggested delay in 22 VLBW infants and 32 control infants, which was not substantiated by professional examination (P=0.006). In contrast, examination-diagnosed delay was missed by the questionnaire in one infant in each group. The R-PDQ is a reliable monitoring instrument for both VLBW and term infants at the age of 12 months. Parents of VLBW infants tend to underestimate their infants' development.