The period following childbirth is a time of significant transition for postpartum women. It is a sensitive time and various practices are applied by these women to protect their health and newborn. Little is known about the engagement of health promotion practices of postpartum women in Abia State; and no empirical data was identified in Abia State hence the motivation to determine socio-demographic determinants of health promotion practices among postpartum women attending primary health care centers in Abia State. To achieve this purpose, 16 specific purposes, and 16 corresponding research questions and 16 hypotheses were raised. Descriptive survey design was adopted. Multi-stage sampling technique was used to draw 600 postpartum women attending primary health care centers at Abia State between September and October, 2021. Research instrument was a researcher- developed questionnaire tagged “Health Promotion Practices Questionnaire, (HPPQ)” which was divided into four clusters (adequate nutrition, rest and sleep, breastfeeding and personal hygiene). Three experts validated the instrument. The HPPQ was subjected to reliability test using Kuder-Richardson (K-R 20) and the reliability coefficients of 0.74, 0.73, 0.61 and 0.69 were obtained for adequate nutrition, rest and sleep, breastfeeding and personal hygiene respectively. Analysis was done using 462 adequately completed copies of the instrument. Frequencies and percentages were used to answer the research questions, while chi-square statistics was used to test the hypotheses at.05 alpha levels. The findings showed that greater proportion of women below 23years of age engaged less in health promotion practices regarding adequate nutrition, rest and sleep. Based on the above findings, conclusions were drawn and recommendations among others were made: every postpartum woman should be adequately informed and sensitized on the importance of postpartum care and the essence of regular attendance to Primary Health care centers during postpartum period, particularly the younger ones, using appropriate channels and settings.