The presence of supernumerary teeth (STs) may give rise to a variety of clinical problems. These include failure of a tooth to erupt, delayed eruption, ectopic eruption, diastema, rotation of adjacent teeth, displacement of teeth and crowding. This case describes a 14-year-old male patient who presented with the complaint of pain in the left mandibular posterior region. Intraoral examination revealed the presence of carious retained deciduous second molar in this region. An orthopantomogram was advised which 'initially' revealed 11 STs, positioned in all four quadrants in posterior regions. Two more STs were detected in the following investigations totalling 13. Dental literature rarely reports presence of STs in such a large number. The objective of this case is to report detection of STs, radiographic examination, extraction of the retained deciduous molars and STs in the mandible to facilitate eruption of mandibular premolars.