This chapter focuses on progressive hoarseness and persistent stridor. A child with progressive stridor and persistent hoarseness with no signs of toxicity is likely to have recurrent respiratory papillomatosis (RRP). It is the presence of wart-like proliferations of keratinized squamous cells, containing the human papilloma virus (HPV), in the aerodigestive tract, and most frequently, the larynx. RRP in childhood is called juvenile onset RRP (JORRP) and in adulthood it is called adult onset RRP (AORRP). A child with a hoarse voice always needs to have a careful history taken to exclude RRP. Concerning features are voice, breathing effort, breathing sound, nonspecific symptoms and birth history. This chapter aims to present a brief discussion on epidemiology, pathophysiology, presentation, investigations, management and prognosis of RRP.