The empty follicle syndrome (EFS) is a frustrating condition in which no oocytes are retrieved in an IVF cycle. Although this is an infrequent event in IVF patients, the economic consequences as well as the emotional frustration of a cancelled cycle due to the inability to obtain oocytes are enormous. The mechanisms responsible for EFS remain obscure, though many hypotheses have been put forward ranging from dysfunctional folliculogenesis to a drug-related problem. We found that the EFS is a rare event (1.8% of oocyte retrievals) but with profound implications for counselling the couple about their future reproductive performance. The chances of recurrence of EFS increase with the age of the patient (24% recurrence rate for the 35-39 year age group, and 57% for those over 40 years). We postulate that ovarian ageing, through altered folliculogenesis, may be implicated in the aetiology of EFS and its recurrence.