This study was undertaken to determine differences in microflora on the nails of health care workers (HCWs) wearing artificial nails compared with control HCWs with native nails and to assess the effect on these microflora of hand cleansing with antimicrobial soap or alcohol-based gel. Cultures were obtained from 21 HCWs wearing artificial nails and 20 control HCWs before and after using antimicrobial soap or alcohol-based gel. Before cleansing with soap, 86% of HCWs with artificial nails had a pathogen (gram-negative bacilli, Staphylococcus aureus, or yeasts) isolated, compared with 35% of controls (P=.003); a similar difference was noted before hand cleansing with gel (68% vs. 28%; P=.03). Significantly more HCWs with artificial nails than controls had pathogens remaining after hand cleansing with soap or gel. Of HCWs with artificial nails, only 11% cleared pathogens with soap compared with 38% with gel. Of control HCWs, only 14% cleared with soap compared with 80% with gel. Artificial acrylic fingernails could contribute to the transmission of pathogens, and their use by HCWs should be discouraged.