OBJECTIVE: To determine whether differences in the osteochondral junction (OCJ) in two different age groups could be detected with ultrashort time-to-echo (UTE) MRI in vivo. METHODS: 10 healthy controls aged 20–30 years (Group 1) and 10 patients aged 40–50 years with knee pain but no evidence of osteoarthritis (OA) (Group 2) underwent 3-T MRI of the knee using a two-dimensional UTE sequence. Evaluation of the presence/absence of a high-signal-intensity (SI) line at the medial tibial/lateral tibial (MT/LT) OCJ was performed. Regions of interest (ROI) were created at the MT OCJ and LT OCJ. The peak OCJ SI ratio was calculated by measuring peak OCJ SI using averaged craniocaudal SI profiling, then dividing by the mean SI of a background ROI to standardize between studies. Groups were compared using χ2 and Mann–Whitney U tests. RESULTS: A high SI line was present in significantly more Group 1 subjects at both MT (p < 0.001) and LT (p = 0.002). There was a significant difference (p < 0.001) in MT peak OCJ SI ratio between Group 1 (mean ± SD = 0.85 ± 0.10) and Group 2 (0.77 ± 0.12). There was no significant difference (p = 0.19) in LT peak OCJ SI ratio between Group 1 (0.81 ± 0.23) and Group 2 (0.80 ± 0.13). CONCLUSION: Significant differences in the UTE MR characteristics of the OCJ were demonstrated between the two age groups. ADVANCES IN KNOWLEDGE: Alterations in the UTE appearances of the tibial plateau OCJ in the older group with knee pain compared with a younger, healthy control cohort may reflect the very early stages of OA.