Aim: to evaluate Plantar Fasciitis (PF) by Ultrasound (US). Methods: fifty patients (29 bilateral, 21 unilateral) and 13 healthy subjects were studied by US. The thickness, echogenicity and margins were assessed. Results: plantar fascia thickness was significantly increased in bilateral and unilateral symptomatic heels than asymptomatic heels for patients with unilateral PF and than the controls. Hypoechogenicity was present in 80 % of the cases. The margins showed convex bulging. Conclusion: the findings by US can provide sufficient information to confirm the clinical diagnosis.