After a careful examination of the works of Čajkanović, the author points out to the importance of his comparative method in studying Ancient Greek literature, traditional folk creation and folk religion and mythology. Based on traces and parallels from other traditions, Čajkanović tried to reveal the forgotten meanings of the Serbian folk myth and religious practice. With this same approach, he attempted to reconstruct the whole system of an ancient Serbian religion and mythology, and to establish an identity of the Serbian supreme God. However, a critical review of this reconstruction shows its inaccuracy and scientific dismissal.