To determine whether patients undergoing radiotherapy would choose to attend appointments for a course of treatment scheduled outside the normal working day and working week. A survey of radiotherapy outpatients was conducted on two single days in late 2005 and early 2006. There were four departments in the first cohort and five in the second cohort. Departments were selected from across the UK and were chosen to reflect both city centre and out of town locations. Six of the nine departments were working extended hours at the time of the survey. The second cohort received a modified questionnaire that included two additional questions relating to appointments at weekends. There is sufficient support from patients for attendance outside the normal working day to ensure appointment slots would not go unfilled during a moderate extension to the working day. However, the percentage of patients that would attend varied between departments. This demonstrates the need for local evaluation of patient preference before the introduction of extended working hours.