The after hours GP helpline (AGPH), one of the key services provided by Healthdirect, is an extension of the existing healthdirect telephone nurse triage and advice service. It provides access to telephone health advice by GPs after hours to patients/callers who are triaged by the telephone nurse as needing to see a GP immediately, within four hours or within 24 hours. The aims of this study were to assess patient satisfaction with the AGPH service and compliance with the GP advice; and to investigate factors associated with patients' compliance. This study included 2486 patients/callers who used the AGPH and participated in a survey between February and September 2013. Over 97.1% of patients/callers were either satisfied or very satisfied with the AGPH service. Compliance was measured in two ways: i) self-reported compliance to advice provided; and ii) matching of self-reported actions with actual GP advice given: 94.0% of patients reported they followed the advice given to them by GPs and for 86.8% of patients their reported actions following consultations matched the recommended advice documented by GPs in the healthdirect database. Patients' compliance with recommended advice were associated with patient overall satisfaction with the service, the type of AGPH advice received, and the estimated severity level of the conditions. Improving patient satisfaction with the service along with patient understanding of the advice can lead to an increased compliance rate.