Ciprofloxacin tablet was characterized by x-ray photoelectron spectroscopy. The sample was fixed to a stainless-steel sample holder with copper double-sided adhesive tape. Survey spectrum, C 1s, O 1s, N 1s, F 1s, Cl 2p, Mg 1s, and Si 2p core levels spectra were acquired. The results point out the presence of carbon, oxygen, nitrogen, and fluorine elements that constitute the ciprofloxacin; however, carbon and oxygen are also found in other ingredients (excipients). Additionally, chlorine, silicon, and magnesium were also detected, which are related with excipients.