Evidence of Kaštiliašu's kingship is somewhat circumstantial. He may be the person indicated on line 12 of the Synchronistic King List who is preceded by a lacuna and superseded by a poorly preserved name which is unlikely to be Ulam-Buriaš. Two passages in the Chronicle of Early Kings mention Kaštiliašu: "Ulam-Buriaš, brother of Kaštiliašu, the Kassite" and "Agum, the son of Kaštiliašu". (Ulam-Buriaš conquered and ruled the Sealand—at the southern end of Babylonia—and perhaps ruled as king of Babylonia; Agum (III) was king of Babylonia.) He has no royal title in those, a feature of this chronicle that is shared by others, such as Samsu-Ditana, who did prove to be kings.
- J. A. Brinkman (1976). Materials for the Study of Kassite History, Vol. I (MSKH I). Oriental Institute of the University of Chicago. pp. 12, 13.
- Albert Kirk Grayson (1975). Assyrian and Babylonian chronicles. J. J. Augustin. p. 249.
- Jona Lendering. "Chronicle of early kings (ABC)". Retrieved July 30, 2011.