So far as is now known, only two comedias from the pen of Tirso de Molina have survived in holographic form; they are the first and the third parts of the Sancta Juanna trilogy. In the study to follow, the two comedias will be investigated in their orthoëpic aspects. The findings may serve as a check on those discovered by previous investigators in texts which are not in holographic form. Some years ago Mr. Morley published a study of the orthoëpy of five of Lope's plays. The present investigation resembles that of Mr. Morley, and the excellent outline which he developed for his compilation is followed below; the deliberate parallelism of our procedure with his facilitates comparison between Tirso and Lope in the matter under discussion. In Part I there will be presented a tabulation which concerns the individual word with its various combinations of vowels, weak and strong, tonic and atonic, in pretonic, tonic or post-tonic syllables, in diphthong, dieresis, syneresis or bisyllabism. In Part II of the compilation there is offered a consideration of the combinations of the words in synalepha or hiatus under varying conditions.