PURPOSE: The purpose of this study was to estimate the frequency of and describe the clinical characteristics and complications of patients with nonsyndromic multiple mandibular supernumerary premolars. PATIENTS AND METHODS: Among 110,500 patients seen between July 2003 and January 2007, 32 cases of multiple (2 or more) mandibular supernumerary premolars were found. Data including age, gender, number, distribution, and location of supernumerary premolars, extraction procedure, and related complications (such as cystic changes, root resorption, or adjacent teeth eruption disturbance) were collected. RESULTS: Six of 32 patients were female; the male to female ratio was 4.3:1. Prevalence of non-syndromic multiple mandibular supernumerary premolars was 0.029%. Mean age was 17.8 years. Root resorption of an adjacent tooth was found in 1 patient. Eruption anomalies were found in 5 patients and included impaction of a permanent tooth, prolonged retention of a deciduous tooth, and displacement of an adjacent tooth. Supernumerary teeth locations were predominantly lingual except for 4 teeth. CONCLUSION: Prevalence found in this study was lower compared with previous studies. However, the rate of related complications was higher, even though the mean age was relatively low. Surgical intervention should be considered to prevent unwanted sequelae for any signs of complication.