Objective: To report on the use of the New Zealand Quitline for recruiting participants to a smoking cessation trial. Methods: Analysis of data on trial recruitment and randomisation. Results: 68% of 26,369 callers to the New Zealand Quitline over 12 months indicated an interest in taking part in research, 28% of whom met eligibility criteria for a cessation intervention trial, assessed on the data routinely collected at Quitline registration. Of these, 1317 (26%) were contacted by call back with 1027 (78%) agreeing to take part in the trial. After further eligibility checking 851 people were randomised. Weighting of calls ensured that 25% of participants were Maori. Conclusions: Quitlines have good potential to be an effective means of randomising participants into cessation trials and ensuring adequate representation of underrepresented population groups.