Primary double teeth (PDT), referring to either gemination or fusion, are one of the most important and frequent developmental dental anomalies that can affect children's oral health. Many clinical complications are correlated with these anomalies, such as dental caries, malocclusions, periodontal problems, and dental anomalies in permanent dentition. The aim of this report was to describe, through two cases, a case of gemination and another of fusion, the clinical management, the consequent effects, and the possible repercussions of these two developmental abnormalities on permanent successors. The first case involved gemination of the primary maxillary left central incisor (#61) in a 6-year-old boy. The patient presented with dental caries in the geminated tooth and its contiguous primary left lateral incisor (#62). The radiological examination revealed a slight developmental delay in the permanent left lateral incisor (#22). The treatment plan involved performing a pulpotomy and restoring the dental crowns of the affected teeth. The second clinical case describes a 6-year-old girl with unilateral fusion between a primary mandibular lateral incisor (#72) and a supernumerary tooth (#72'). The treatment included restoration of the deep grooves of the fused teeth using flowable composite and coronal restoration of the contiguous left primary canine (#73). Clinical and radiological follow-ups were performed every 3 months to monitor the development of teeth. No clinical and radiological symptoms were noted during the follow-up visits. PDT may require a multidisciplinary treatment. They should be diagnosed early to avoid and treat any possible complications in both the primary teeth and their permanent successors.