In recent decades, the relation between Egyptian and Greek praises of the goddess Isis has received much scholarly attention. The present study, however, focuses on six Demotic hymns and praises directed to this goddess: P. Heidelberg dem. 736 verso, O. Hor 10, Theban Graffiti 3156, 3462, 3445, and P. Tebt. Tait 14. These texts from the second century BC to the second century AD are re-edited in facsimile, transliteration and translation. A commentary to each document discusses philological matters, providing improved readings in some instances. For the first time, the six texts are analyzed comparatively in regard to formal features and content. The concept of Isis that is outlined by the Demotic sources is set against Isis' role as described by other Egyptian sources (such as temple inscriptions or theophoric personal names) and by Greek eulogies of the goddess. An appendix offers an overview of other Demotic hymns and praises addressed to various divinities.