An ideal pulpotomy agent for primary molars has been sought for many years. Recently, new materials that allow regeneration of residual pulp tissue have been developed. In this study, we compared the preliminary clinical results obtained using Biodentine and mineral trioxide aggregate (MTA) as pulp-dressing agents in pulpotomies of primary molars. A randomized clinical study was performed in children aged 4-9 years with at least one primary tooth with decay or caries requiring pulp treatment. A total of 90 primary molars requiring pulpotomy were randomly allocated to the MTA or Biodentine group, and 84 pulpotomies were performed. Clinical and radiographic evaluations were undertaken 6 and 12 months after treatment. All teeth were restored with a reinforced zinc oxide-eugenol base and stainless steel crowns. Statistical analysis using Fisher's exact test was performed to determine the significant differences between the groups. A total of four clinical failures were observed; all involved gingival inflammation. The clinical success rate in the MTA Group after 12 months was 92 % (36/39), whereas the Biodentine Group obtained 97 % (38/39) (p = 0.346). All radiographic failures were observed at the 12-month follow-up evaluation. One molar from MTA Group showed internal resorption obtaining a radiographic success rate of 97 % (38/39). Two molars from the Biodentine Group showed radiographic failure (1 internal resorption and 1 periradicular radiolucency) obtaining a radiographic success rate of 95 % (37/39). Biodentine showed similar clinical results as MTA with comparable success rates when used for pulpotomies of primary molars. However, longer follow-up studies are required to confirm our findings. This article demonstrates the effectiveness of Biodentine as a primary teeth pulpotomy material, performing similar results as MTA at 12-months evaluation.