Purpose: To assess the degree of agreement of anterior chamber depth (ACD) measurements by optical device (NIDEK AL-scan biometer) and contact ultrasound A-scan (Mentor ^[R] - Advent ^[TM] A/B system US biometry). Setting: Department of Ophthalmology at ALAZHAR University, Cairo, Egypt. Methods: This prospective observational cross sectional comparative study of 50 normal healthy eyes were included in this study, ACD estimation was done by 2 methods partial coherence interferometry (PCI), and contact ultrasound A-scan.  The measurements were performed by the same observer. The difference in measurements between the two methods was assessed using the t-test. Results: The mean ACD (±SD) by the two methods were (2.8 mm) and (3.5 mm), respectively. There was a statistically significant difference between measurements recorded by the 2 methods (P<0.01). Conclusion:  there was a statistically different between the two methods the PCI values were significantly higher (by 0.7 mm) than the U/S values with no correlation between the two sets of values. So, PCI is more accurate but we still need U/S measurements in some situations (e.g., tear film abnormalities, corneal pathologies).