Mediator complex subunit 12 (MED12) is a part of the mediator complex, which is believed to regulate transcription. MED12 is mutated at high frequency and with different mutation frequencies in uterine fibroids and breast fibroadenomas of different populations. This study aimed to analyze MED12 mutations in Senegalese population. MED12 was sequenced in the tumoral tissues and blood samples of Senegalese women with uterine fibroids or breast fibroadenomas. Surveyor software version 5.0.1, DnaSP version 5.10, MEGA version 6.06 and Arlequin version 3.5.1.3 were used to determine the level of mutations and genetics parameters. Our results showed the presence of variants in the tumoral tissues only, with most of them being heterozygous single nucleotide polymorphisms. Deletion in polyA tail was identified for the first time in the studied population. Data also showed that MED12 exon 2 was under positive selection in case of uterine fibroids and breast fibroadenomas. The variants frequencies were not similar to those found in the Finnish or Southern United States populations for cases of uterine fibroids, and to Japanese population for cases of breast fibroadenomas. These results suggest that MED12 variants could contribute to the development of uterine fibroids and breast fibroadenomas. The present study contributes to the current information on MED12 variations in different populations and may aid in the development of personalized diagnoses for patients with uterine fibroids or breast fibroadenomas in the future.