In the framework of a complete concordance of the poetical works of the Spanish dramatist Pedro Calderón de la Barca, a concordance of the Autos Sacramentales has been produced first. The edition by Angel Valbuena Prat (Madrid, 1952) was chosen from among numerous editions to serve as base text. The concordance lists every word form in alphabetical order. Each occurence is recorded along with the context of the line. The first volume includes a detailed preface. The Autos Sacramentales are of growing importance to linguists and students of literature, theology, philosophy, history, and sociology. To all such scholars this concordance will open up these difficult texts for criticism and commentary. Part 2 of the Calderon concordance is being prepared by Jürgen Rolshoven and Manfred Tietz. It is also based on the Aguilar edition and covers the Comedias y Dramas.