The records of 50 Australian postpartum women who intended to breast-feed for longer than 6 months were analyzed. Fifty percent of the women breast-fed longer than 12 months, and 50% resumed menses by 40 weeks after childbirth. Fifty-four women provided records of mucus and BBT for at least 4 weeks before resumption of menses. Ovulation before menses while fully breast-feeding was probable in only one woman. Fifty percent of the first postpartum cycles had a short luteal phase. Thirty-two women chose NEP to avoid pregnancy during the study period. Mucus and BBT proved to be a good marker of ovulation during postpartum cycles. The mean number of days available for intercourse according to the Ovulation Method was 22.6 days between 6 and 12 postpartum weeks, and 12 days during the 4 weeks before menses. Confidence in NFP during lactational amenorrhoea and first postpartum cycles is analyzed. Finally, research aimed at improving the teaching and use of NFP for postpartum breast-feeding women is described.