There are no published data on the efficacy of online first aid or resuscitation learning programmes in Australia. Our goal was to compare the knowledge and first aid skills of subjects who have undertaken the St. John Ambulance Australia (WA) "online crash course", with those who have no first aid training. We evaluated first aid knowledge and basic life support (BLS) skills of two groups of students. The control group (n = 11) had received no first aid training of any type and the test group (n = 12) had undertaken and passed the St. John Ambulance online "crash course". This course is purely theoretical. BLS skills were assessed using standardised patients and manikins. Knowledge was assessed by a written assessment. Assessors were blinded to which group the students belonged. There were significant differences in the performance of the written test, between the group who completed the course and the group who did not complete the course (P = 0.036: Mann-Whitney U-test). There were no significant differences in the performance of any other practical tasks between the two groups. We conclude from this that the online course improved course participant's knowledge of BLS significantly, but not their ability to perform; that online first aid courses may be useful for knowledge acquisition but that they do not confer any benefit, in performance of BLS skills.