Introduction: Duration of post-partum amenorrhoea (PPA) is the period from the end of pregnancy to begin of menstruation. It is a temporary infecundable period. The attainment of first menstruation after delivery is treated as the termination of PPA.

Objectives: The main aim of this paper is to investigate the differentials of the duration of PPA according to the characteristics of mothers and their child.

Methods: The data are taken from a sample survey of Palpa and Rupandehi districts. A total of 1019 ever-married mothers were interviewed. 481 mothers were provided information on the duration of PPA to their last but one born child (retrospective status reporting). Survival analysis technique has been used.

Results: It was found that the distribution of PPA showed a heaping at the multiple of three months. Mean duration of PPA was found to be ten months and it was higher among mothers of higher parity, older mothers and higher age at birth of child. Younger mothers have lower duration than that of the older. Mean duration was increased with the increased parity of mothers. A strong positive association was observed between the duration of PPA and breastfeeding (BF). The increased duration of PPA was found with the increased birth interval. The survival status of child was found a strong consequence on amenorrheaic period. Inverse association was found with education as well as high socioeconomic status of the family. A significant association was found with residential as well as caste/ethnic groups.

Conclusion: Mean duration of PPA was found to be 10.6 months. Amenorrheaic period was found higher among mothers of higher parity, older ages, and higher age at birth of the child. A positive relationship was found with BF whereas inverse association was found with the level of education. Duration of PPA was decreased with the increased level of socio-economic status.