The Crimson Topaz, Topaza pella, is the least known of the two hummingbird species of this exclusively Amazonian trochilid genus, that also includes T. pyra. Most available information on T. pella nests, young and reproductive behavior is based on anecdotal observations from Guyana in the 1930s and 1950s. Here, we provide new data on nest description, eggs and parental care of T. pella, and the growth and development of two nestlings over a 22-day period. We studied four nests in areas of dense terra firme forest in the state of Amapá, Brazil. All nests were in forked branches of shrubs over water bodies, and had a cup-like form. One nest contained two elongated white eggs, and another, two nestlings, which had their development recorded until they left the nest. (AU)