Savard et al. report that binary angiographic classification of renal artery fibromuscular dysplasia (FMD) lesions as 'unifocal' or 'multifocal' FMD (defined as <2 stenoses and ≥2 stenoses in the same arterial segment, respectively) is clinically relevant. At the time of FMD diagnosis, patients with multifocal lesions (n = 276) were older (median 49 years versus 30 years) and had lower blood pressure than those with unifocal lesions (n = 61). The proportion of male patients and the prevalence of unilateral renal artery lesions and kidney asymmetry were also lower in the multifocal group.