Guacho (Foundling) was based on a novel by Concha Espina. The scene is a tiny Argentine fishing village, where a handsome newcomer (Carlos Cores) marries a local girl (Tita Merello). A year or so later, an abandoned baby is left on the couple's doorstep. The wife is of the opinion that the child belongs to the young woman (Julia Sandoval) whom her husband had jilted just before the wedding. Comparing the healthy foundling to her own sickly child, the wife switches babies so as to strengthen her hold on her errant husband. It is inevitable, then, that the mother of the abandoned child will make an untimely reappearance before the story has ended.
~ Hal Erickson, All Movie Guide