Objective: To compare the diagnostic value of transcranial color Doppler sonography (TCCS) with contrast-enhanced transcranial color Doppler sonography (CE-TCCS) for the detection and characterization of intracranial aneurysms. Methods: Thirty patients highly suspected of having an intracranial aneurysm were imaged using TCCS and CE-TCCS. The ability to detect the aneurysms and determine their size and location accurately was compared with findings from digital subtraction angiography. Results: The overall sensitivity of CE-TCCS was greater than that of TCCS (24/30 versus 20/30, respectively) (p = 0.125), but the difference was not significant. Neither TCCS nor CE-TCCS could detect the three small (=5 mm diameter) aneurysms. The detection rate for larger aneurysms (515 mm diameter, n = 17) was nonsignificantly greater with CE-TCCS (14/17) than with TCCS (11/17) (p = 0.438). Similarly, CE-TCCS detected more large or giant aneurysms (>16 mm diameter) than TCCS (10/10 versus 9/10, respectively) but the difference was not significant (p = 1.000). The benefit of contrast enhancement was identical for aneurysms =10 mm or <10 mm in diameter. All (7/7) middle cerebral artery aneurysms were detected by both TCCS and CE-TCCS. CE-TCCS yielded similar or slightly better results than TCCS for all other aneurysm locations. Conclusion: CE-TCCS can improve the sensitivity and detection rate of intracranial aneurysms =5 mm in size. (c) 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2012