The information presented in this article demonstrates that unilateral or bilateral vocal cord paresis or paralysis in infants and children is difficult to diagnose and difficult to manage. In an attempt to provide the otolaryngologist with a concise set of relevant guidelines, the following rules for management are presented here. 1. Suspect bilateral abductor vocal cord paralysis (BAVP) when a neonate or infant presents with high-pitched inspiratory stridor and evidence of airway compromise. Factors that should increase the suspicion of BAVP include associated Arnold-Chiari malformation; congenital anatomic abnormality involving the mediastinum (for example, tracheoesophageal fistula, vascular ring, other vascular anomalies); dysmorphic syndromes, especially those involving brainstem dysfunction; and manifest findings indicative of neuromuscular disorder. The neonate or infant with Arnold-Chiari malformation and inspiratory stridor has bilateral abductor vocal cord paralysis until proven otherwise. 2. Suspect unilateral vocal cord paresis or paralysis in an infant or child with hoarse voice, low-pitched cry, or breathy cry or voice. The infant who develops mild stridor and hoarse cry following surgical repair of a patent ductus arteriosus or tracheoesophageal fistula has a unilateral vocal cord paralysis until proven otherwise. 3. Direct laryngoscopy with the flexible fiberoptic nasopharyngolaryngoscope and photodocumentation using a videocassette recorder offers the best method for diagnosis of vocal cord paresis or paralysis. Additional diagnostic studies that may be helpful include radiographic studies, CT scan, MRI scan, electromyography of the larynx, and, in older children, stroboscopy. 4. In using a flexible direct laryngoscope be careful not to interpret all motions of the vocal cords or arytenoids as evidence to preclude the diagnosis of vocal cord paralysis or paresis and be careful not to mistake the anterior intraluminal portion of a normal cricoid for an "anterior glottic web." 5. Tracheotomy is often required in order to assure adequate airway during infancy for children with BAVP. However, with the advent of sophisticated cardiorespiratory monitoring equipment and methods for monitoring blood oxygen and carbon dioxide levels, tracheotomy can be delayed until attempts have been made to improve the adequacy of the airway with neurosurgical intervention or other procedures.(ABSTRACT TRUNCATED AT 400 WORDS)