Skin and soft tissue abscesses are commonly treated in emergency departments (ED). The use of bedside ultrasound may improve patient outcomes. The primary objective of this study was to examine the relationship between ultrasound use and risk of treatment failure in ED patients treated for abscesses. In this multi-center observational study, we reviewed medical records of adult patients evaluated for abscesses. Demographics, infection characteristics, treatments rendered, use of ultrasound (for diagnosis and/or treatment) and follow-up data were collected from electronic medical record review. Treatment failure, the primary outcome, was defined as any surgical intervention after the initial ED visit. Multivariable logistic regression tested whether incision and drainage utilizing ultrasound was associated with reduced treatment failure. We identified 609 patients diagnosed with abscesses over a 22-month period. Of them 75% were treated with incision and drainage, 55% had an ultrasound and 15% failed treatment. Multi-variable analysis demonstrated an 8% probability of failure with ultrasoundplus incision and drainage, 14% with blind incision and drainage and 25% without incision and drainage. Individuals with incision and drainage performed were 50% less likely to fail treatment (RR 0.53, 95%CI 0.35-0.81) and 70% less likely to fail treatment (RR 0.30, 95%CI 0.18-0.51) with ultrasound and incision and drainage. The use of ultrasound in diagnosing and or/treating patients with abscesses in the ED is associated with decreased treatment failure risk when utilized with incision and drainage. Consideration of ultrasound use in other studies which assess treatment methods in relation to patient outcomes may be warranted.