This study examines fertility decline that is larger than expected on the basis of recorded increases in contraceptive prevalence in Ghana. The primary sources of data are three Demographic and Health Surveys (DHS) conducted in the country in 1988, 1993 and 1998. First, the trend in fertility and contraceptive prevalence in Ghana is considered and compared with the trend that would be expected on the basis of prior research. Next, an attempt is made to uncover the explanation behind this unexpected trend. Measures of the quality of the survey data are looked at, as well as trends in the proximate determinants of fertility: contraceptive use, marriage and sexual activity, postpartum insusceptibility and induced abortion. Finally, evidence is presented that couples adjust their coital frequency in accordance with their fertility preferences, behaviour that would influence fertility rates but would not be captured by conventional measures of the proximate determinants of fertility.