After drawing up an inventory of Dakar markets popular medicinals plants, antimicrobial activity of 43 species have been screened. With the agar diffusion method, crude extracts of 24 species show an activity against Sarcina lutea or Escherichia coli. The antimicrobial spectrum of these extracts against 11 germs has been evaluated with the agar dilution method. 13 species show M.I.C. lower than 10 mg/ml against some germs. This preliminary study select some plants of potential interest for development of new antibacterial.