Flammulina festiva Scott, 1970 is a terrestrial gastropod endemic to southern Chile. Characteristics of living specimens, including the anatomy of the excretory and reproductive systems of this species are here reported for the first time. The excretory system of this species is of the charopid type with a short, curved primary ureter, and a secondary ureter which extends to the excretory sinus. The reproductive system exhibits characteristics similar to other Charopidae. There is an ovotestis that is divided into seven lobes, a well-developed albumin gland, an ovospermial duct with a proximally diverticulate, distally undivided prostatic gland, plus a short oviduct. The terminal portion of the system shows a pointed epiphallus, and a phallus within a phallus sheath. Direct observations in the field suggested this species was active during the day, mainly under decomposing logs, fallen leaves, and under dense, ground-level vegetation in this humid biogeographic zone.