PURPOSEThis study aimed to determine the prevalence and underlying causes of pedal edema (PE) in legs affected by chronic edema.PROCEDURESA total of 705 legs with chronic edema, defined as persistent leg edema lasting for > three months, were examined in 411 patients who visited our clinic between April 2009 and March 2024. Patients with known systemic edematous conditions or those with serum albumin levels < 3.5 g/dL and/or an estimated glomerular filtration rate < 60 mL/min/1.73 m2, as confirmed during screening blood tests at their initial visits, were excluded from the study. The presence of edema in the leg, including the pedal region, was confirmed using ultrasonography to detect subcutaneous echo-free spaces. Routine assessments included blood screening, duplex venous scans, and skin ultrasonography. Air plethysmography, lymphangioscintigraphy, and bioelectrical impedance analysis were performed whenever feasible.RESULTSThe prevalence of PE in legs with chronic edema was 64%. Multivariate analyses identified the severity of subcutaneous echo-free space in the lateral lower calf, which correlated with the overall severity of leg edema (odds ratio [OR]: 5.62; 95% confidence interval [CI]: 2.46-14.62; p < 0.001), and serum albumin level (OR: 2.55; 95% CI: 1.31-5.05; p < 0.01) as significant risk factors for PE.CONCLUSIONSPE was present in 64% of legs with chronic edema. The primary contributors to PE were the overall severity of leg edema and lower serum albumin levels, even within the normal range.