Clinical MRI techniques typically show the anterior cruciate ligament (ACL) as low in signal. Commonly used quantitative MRI techniques are sensitive to tissue orientation and magic angle effect. A recently developed ultrashort echo time (UTE)-based adiabatic T1ρ technique (UTE-Ad-T1ρ) can detect high signal in the ACL and may be less sensitive to magic angle effect. We have investigated for the first time the correlation between UTE-Ad-T1ρ and ACL mechanical properties. T1ρ showed significant strong correlation with average elastic modulus of ACL specimens. The UTE-Ad-T1ρ technique is highlighted as a potential tool to noninvasively assess the ACL mechanical properties.