Standard toilet training regimens used with children with developmental disabilities have demonstrated effectiveness at achieving bladder and bowel continence. However, in some clinical applications in everyday practice, success has not been achieved, necessitating research into possible modifications of the current approaches. A widely used toilet training program was modified to reduce toileting accidents of a referred child. The modification involved the assessment of the discriminative stimulus for eliminating, namely, his undergarments. By removing the undergarments when an elimination became imminent, an "errorless" learning paradigm was established that allowed for more rapid and enduring acquisition of toileting skills than seen in previous training attempts. The results indicate the present procedure could expedite training for individuals who are difficult to teach appropriate toileting skills through an analysis of the controlling antecedent stimulus for accidents and subsequent manipulation of such stimuli.