Objective — to define more precisely the potential of magnetic-resonance imaging (MRI) in the early diagnosis of coxitis in patients with spondyloarthritis (SpA). Material and methods. Hip (coxofemoral) joint (HJ) MRI (in T1 and T2Fat Sat; 1,5 T modes) was performed in 60 patients with ankylosing spondilitis (AS) and SpA: clinical signs of coxitis were present in 37 patients, while remaining 13 patients without coxitis were included into the control group while 10 healthy subjects without SpA made formed a healthy control group. The following parameters were monitored: pain intensity — by the numeric rating scale (NRS 0—10), distance between the ankles, radiographic changes (RCh) by BASRI index, presence of intraar-ticular exudate by US-examination. Active coxitis was defined as pain (during active and/or passive movement and/or pain at rest) in hip joint after exclusion of enthezitis-related pelvic or greater trochanteric pain. Results. Cases of AS and SpA aged younger than 20 y.o. predominated in the cohort patients with coxitis (55,2%). Bilateral coxitis was diagnosed in 81% patients. Median (Me) of disease duration was 12 [25th; 75th percentiles — 1; 132] months. Pain intensity in hip joint measured by NRS was 3 [2; 5]. RC were not found (BASRI-hip=0) in 20 (29,8%) affected joints, 47 joints met the criteria of I—III BASRI-hip stage. RCh were not present in patients without coxitis (BASRI-hip=1) in 9 (28,7%) joints. The most prevalent inflammatory changes (ICh) in patients with coxitis following MRI data were: exudation in the articular space >7 Ml (54%), bone marrow edema (BME) in the acetabular region (39%), cysts of the acetabular roof (32%), capsule thickening (25,5%), BME of the femoral head (13,4%), cysts of the femoral head (10%). There was a significant correlation between pain intensity measured by NRS and prevalence of ICh (Spearman's rank correlation R=-0,29; t=-2,46; p=0,01). BME of the femoral head and/or of the acetabular roof were seen significantly more often in patients with RCh (in 64 and 25% joints, respectively; p=0,0005). BME of the acetabular roof was 3-fold more common than BME of the femoral head (39 and 13,4%; p=0,001). Femoral head cysts were detected in 15% of joints in the subgroup of patients with RCh, and in 8,5% of joints in the subgroup of patients without RCh (p=0,4). Acetabular roof cysts were seen only in patients with RCh (32%). Overall ICh were detected in 55 (82%) joints in patients with coxitis and in 4 (12,1%) — without coxitis (BME — 1; exudation — 3). In patients without SpA and AS exudation was detected in 5 joints. Conclusion. ICh in hip joint can be detected by MRI before the development of structural damage. The most common area for detection of early inflammatory changes, i.e., BME is the subchondral space of acetabular roof.