The authors conducted a retrospective-casuistic study to determine the prevalence of nonsyndromic multiple hyperdontia in a sample of the population of Madrid, as well as possible complications associated with the presence of such supernumerary teeth.The study included a data assessment of all patients seeking dental care at a hospital's department of oral surgery across four years. The authors studied data from patients who had nonsyndromic multiple hyperdontia. We used univariate and bivariate analysis to make comparisions between variables.The authors identified nonsyndromic multiple hyperdontia in the records of 13 patients (0.1 percent) of the total population studied. These patients had 55 supernumerary teeth. Premolars were the most frequently seen type of supernumerary tooth and constituted 45.5 percent of the sample.Nonsyndromic multiple hyperdontia usually is diagnosed as a coincidental radiographic finding in the course of routine examination rather than as the result of an associated disease. However, the authors found a higher percentage of comorbidity than they initially expected; mechanical or obstructive pathology was associated with 20.0 percent of the supernumerary teeth and enlargement of the follicular sac of more than 3 millimeters was present in 23.6 percent of the sample.The early diagnosis and follow-up of patients with multiple supernumerary teeth should help clinicians prevent the diseases associated with this kind of hyperodontia.