A cross-sectional study was conducted at 33 randomly selected health facilities in Jeddah, Saudi Arabia, to assess health facilities' performance and health workers' knowledge of surveillance activities for childhood vaccine-preventable diseases. The WHO surveillance assessment questionnaire and a specially designed knowledge questionnaire were used. There were deficiencies in some surveillance items. The percentages of health facilities that had the surveillance manual and correctly filled clinical registers were 57.6% and 60.6% respectively. In the 6 months preceding the study, 36.4% of facilities lacked the appropriate surveillance forms while only 18.2% had received supervision reviews. Only one-quarter of health workers had a satisfactory knowledge score.