Battus polydamas archidamas (Boisduval 1836), the only Papilionidae present in Chile, is characterized because its larvae feed exclusively on highly toxic plants of the genus Aristolochia, from which they sequester toxins. Here, we describe the morphology and biology of the larval stages of this butterfly and its eggs. Based on observations using stereomicroscope and scanning electron microscopes, morphological external and some internal descriptions of the 5 larvae instars are provided. Eggs are rounded, 1 mm in diameter and usually covered with a yellow secretion. Presence of mandibular and labial glands are confirmed in all instars. The minimum and maximum length reached by the larvae are 0.32 and 4.82 cm, corresponding to the first and last instar respectively. First instars are dark brown and devoid of any type of scoli. Subsequent instars are generally dark burgundy with two scoli and numerous orange tubercles. In general, the morphology of larval stages is similar to those of related subspecies, with most differences related to its first instar. Data presented here aim to promote and facilitate the utilization of this larva as a study model for further evolutionary and ecological research.