Background: Chondromalacia patellae is damage to the cartilage at the back of the kneecap (patella). Magnetic resonance imaging is a valuable noninvasive technique with a unique ability to image soft tissue and has been used for cartilage evaluation. Objective: This study examines the role of apparent diffusion coefficient (ADC) map and diffusion-weighted imaging (DWI) techniques in diagnosing chondromalacia patella. Materials and Methods: The study consists of 31 participants, 19 patients with chondromalacia patella, and 12 healthy volunteers. The DWI imaging and ADC maps for all patients were recorded. Later the average amount of ADC for a lesion was calculated by drawing regions of interest. Results: The results of DWI imaging in patients with patellae chondromalacia were observed as a nonhomogeneous patella signal and with an increase in the signal intensity at the focal, thickening of cartilage with surface irregularities, reactive changes subchondral, and bone marrow edema. The mean ADC values of the chondromalacia group and the health group were 1.34 × 10–3 mm2/s and 1.07 × 10–3 mm2/s, respectively. Conclusion: Diffusion-weighted imaging can detect early-stage patellar chondromalacia. Besides, it may also help in the detection of cartilage defects.