Having good health-related quality of life (HRQoL) is essential, particularly for women after childbirth.  This study investigated the quality of life and its determinants among lactating mothers in South East Senatorial District, Rivers State, Nigeria. A cross-sectional design was adopted. The population of this study consisted of one thousand, nine hundred and sixty-five (1,965) lactating mothers attending postnatal clinics in South East Senatorial District. The sample size for the study was 983 which was selected using multi-stage sampling procedure. The data collection instrument was a structured questionnaire titled ‘Health Survey Instrument and Health-Related Quality of Life Instrument (HSIHRQoL (SF-12v2)’. Data collected was analyzed with the aid of the Statistical Product for Service Solution (SPSS V-27), using percentage, mean, standard deviation, multivariate regression, and one-way analysis of variance (ANOVA) at 0.05 level of significance. The result showed that the more than three quarter (78.8%) had good quality of life while 21.2% had poor quality of life. The result of the study indicated that there was a very high positive relationship between level of income and quality of life among lactating mothers (r = 0.81). The result further showed that level of income contributed 72.6% of the variance in the quality of life of lactating mothers (R² = 0.726). There was a statistically significant relationship between quality of life and factors such as level of income [f(1,952) = 4521.62, p<0.05], access to healthcare services [f(1,952) = 7817.04, p<0.05], family support [f(1,952) = 6189.10, p<0.05], parity [F(2, 950) = 58.85; p<0.05], age [F(2, 950) = 20.81; p<0.05], and religion [F(2, 950) = 52.84; p<0.05]. It was concluded that lactating mothers in South-East Senatorial District of Rivers State had a good quality of life, which is encouraging and should be sustained. It was recommended among others that quality of life is all-encompassing hence, the postnatal clinics should consider and attend to all the domains of health of both the mother and infant by ensuring that professionals are on ground to discharge their duties both on the social, mental and physical health.

Keywords: Determinants, Lactation, Quality of Life, Mothers, South East.