In the northern parts of Cameroon, Hibiscus sabdariffa seeds are traditionally fermented in earthen-ware pots to produce a condiment known as Mbuja. This study was carried out to access the effect of fermentation on the mineral content of Hibiscus sabdariffa seeds during the process of fermentation. The bacterial species associated with this process of fermentation were screened, numbered and identified at the beginning and at the end of the process. Similarly, the mineral content of grains was determined at these two stages of Mbuja processing. Calcium, magnesium, sodium, aluminium, iron, manganese, zinc and copper were analysed. Results showed that Bacillus and lactic acid bacteria were the main species occurring in the fermentation process. The proportion of each specie varied with the stage of the process. Significant increases were observed in the levels of Mg, Na, Al, Fe, Mn and Zn in the seeds following fermentation. On the other hand, the levels in Ca decreased while Cu levels did not change. A selective diffusion process of minerals is involved.