We assessed hospital infection control knowledge, attitude, and practice (KAP) of healthcare workers (HCWs) during the Hajj season of the Islamic y 1423 (2003). A self-administered structured questionnaire was used to collect the data. A total of 392 HCWs was studied, of whom 215 (54.8%) were nurses and 177 (45.2%) were doctors. 315 (80.4%) HCWs worked in hospitals, whereas 77 (19.6%) worked in primary healthcare centres. Of the 392 HCWs, 164 (41.8%) were from Makkah, and the remaining 228 (58.2%) were recruited from other regions in Saudi Arabia. A good proportion (81.8%) of HCWs correctly answered at least 5 of the 11 knowledge statements. However, obvious deficiency of knowledge appeared concerning other important hospital infection control measures. A smaller proportion (61.9%) of HCWs achieved a score of at least 4 out of 7 for attitude statements with unacceptable attitude for the remaining 3 areas. Response to questions concerning practice showed that nurses tended to be better than doctors (p-value=0.204), but both groups reported variable compliance to hospital infection control practices in terms of strict or near-strict adherence. In conclusion, training of HCWs is needed to improve KAP in infection control.