Background: Radical pulp therapy is an important and a relatively frequent procedure in pediatric dental offices. Aim: This study presents two clinical cases of pulpectomies in deciduous teeth using electronic apex locator and rotary instrumentation. Case descriptions: In Case 1, pulpectomy was performed in a deciduous incisor with diagnosis of pulp necrosis in a 3-year-old patient using an electronic apical locator and manual instrumentation. In Case 2, it was performed in a primary molar with diagnosis of irreversible acute pulpitis in a 9-year-old patient with the use of electronic apical locator and rotational instrumentation. The used technologies contributed to favorable final result of the endodontic treatments in deciduous teeth in both cases. Conclusion: The incorporation of technology to the endodontic treatment of primary teeth favored the gain of time and conicity of the root canal preparation. However, studies still need to be performed to consolidate the technique. Clinical significance: Endodontic treatment of primary teeth still generates much discussion about the materials and techniques employed. The use of electronic apical locator and rotational instrumentation is successful treatment alternatives for teeth with pulp necrosis, with the advantage of limiting clinical time and presenting a favorable outcome.