Pseudomonas aeruginosa and Staphylococcus aureus causes severe infections, especially in nosocomial environments. The cells are often deeply imbedded in biofilms, which makes treatment of the infections extremely difficult. Cells exposed to antibiotic levels below MIC (minimal inhibitory concentration) may develop resistance. The aim of this study was to develop a drug carrier that would keep antibiotic levels, in this case Ciprofloxacin, well above MIC for the duration of treatment. By electrospinning Ciprofloxacin into a nanofiber scaffold consisting of poly(D,L-lactide) (PDLLA) and poly(ethylene oxide) (PEO), the antibiotic was released within 2 h, killing 99% of P. aeruginosa and 91% of a methicillin-resistant strain of S. aureus in a biofilm. Ciprofloxacin, which remained intact, were released from the nanofibers for 7 days at levels above MIC. The nanofibers were not toxic when tested against MCF-12A breast epithelial cells. Antibiotic-filled nanofibers may be the answer to the eradication of P. aeruginosa and S. aureus biofilms.