Prolonged breastfeeding, apart from being beneficial to thechild’s health, helps in keeping the binh rate low. One of the effectsof malnutrition in developing countries is the Teduction in the periodof lactation. In Pakistan, where the binh rate is already very high andthe use of contraceptives limited, any reduction in the breastfeedingperiod may result in an increase of the binh rate. This study wasundertaken to fmd out the recent changes in the breastfeeding patternand their potential impact on the fertility levels in Pakistan. The datafor this study is based on two National Fertility Surveys – the 1975PakistBn Fertility Survey (PFS) and the 1979 Population, Labour Force,and Migration Survey (PLM). The estimation of the mean duration ofbreastfeeding is based on a measure developed by mosley (1982), given bythe formula Y = BIN, where Y = estimate of duration of breastfeeding, B= total number of children currently being breastfed, N = the averagenumber of binhs per mOhth. Taking mother’s age, parity, place ofresidence, education, and occupation as background variables, thefindings are as follows: (1) a decline of about 4 months occurs in theaverage length of lactation; (2) age of mother is positively associatedwith the duration of breastfeeding; (3) urban women have shorter periodsof breastfeeding; (4) women working on farms have longer periods ofbreastfeeding; (5) a slight increase in fertility is due to the declinein breastfeeding and the decrease in the use of contraceptives. It issuggested that breastfeeding may be promoted among Pakistani mothers toreduce the binh rate.