BACKGROUND: Self management programs have been advocated for adults who have recently been admitted to hospital or have recently attended an emergency department because of asthma. A new telephone based approach has already been trialled for the management of a number of other chronic conditions. This study sought to determine the effect of a telephone based asthma management program for adults with asthma. METHODS: Adults with one or more previous admissions for asthma to either or both of two tertiary hospitals between 1 May 2001 and 30 November 2003 were invited to participate. All participants received one face-to-face session with an asthma educator. Participants were randomised to intervention (six telephone calls over 6 months) or control (usual care) groups. Measures of health care utilisation and morbidity were collected weekly for 12 months. RESULTS: Seventy-one adults (54 females) with a mean age of 36.2 years were recruited to the study. Twenty hospital re-admissions were recorded for the control group and one for the intervention group at 12 months. Re-admission was significantly associated with allocation to control group (p=0.05). The control group was significantly more likely to report being woken by asthma on more than half the nights of the week (p=0.03). DISCUSSION: Telephone based self management intervention results in clinically important reductions in hospital re-admission in adults previously hospitalised with asthma.