Despite global awareness about the importance and health benefits of physical activity (PA) during pregnancy, several studies have reported a low prevalence of PA participation among pregnant women in both developed and developing countries. This means that most pregnant women do not meet the current PA recommended guideline of 150 min of moderate intensity PA per week. The global call to prioritise PA participation levels in the general population necessitates evaluating the factors affecting PA practice. Seemingly, pregnant women mostly from low-to-middle income countries like South Africa are often predisposed to adverse pregnancy outcomes, possibly because of limited access to, and knowledge of, improved pregnancy and health outcomes as a result of PA participation. Physical activity has been sparsely studied among pregnant South African women, and specifically, there is no known study that assesses the PA levels, patterns, beliefs, sources of information, perceived benefits, barriers, attitudes of pregnant women concerning PA and exercise participation; nor one that explores the perspectives of healthcare providers regarding prenatal PA in the Eastern Cape Province. In addition, no PA intervention strategy exists to promote PA participation in the region. This study, in attempting to fill these gaps in knowledge, adopts two phases. In Phase I, a concurrent mixed-method (quantitative and qualitative) approach assesses the following factors related to PA participation in pregnant women: participation levels, beliefs, attitudes, perceived benefits, barriers to uptake and sources of information. It further ascertains if healthcare professionals are sufficiently informed about PA and if they are advising pregnant women about the need for PA participation during pregnancy. Data will be collected through a structured questionnaire, interviews and focus group discussions. Information on socio-demographic and maternal characteristics will be obtained, and the Pregnancy Physical Activity Questionnaire (PPAQ) will assess PA during pregnancy. A sample size of 384 pregnant women is the required minimum sample for an infinite population at a confidence level of 95%, a precision level of ± 5% and at a prevalence of PA or exercise during pregnancy of 50% ( < 0.05); however, a sample size larger than the minimum number necessary will be recruited to account for possible attrition and to protect against possible data loss. Data will be analysed using a multiple logistic regression to determine the factors that predict sedentary or moderate PA levels and chi-squared analysis to determine the associations between the PA levels of the participants and socio-demographic and clinical variables. The study will assess the data collected on the above-mentioned variables and draw conclusions based on patterns and themes that emerge during analysis. Phase II of the study focuses on strategy development and validation to facilitate the promotion of PA during pregnancy. The developed strategy will be validated through the application of the Delphi technique and the administration of a checklist to selected key stakeholders through organised workshops. Understanding the level and correlates of PA participation among this special population is fundamental to designing intervention strategies to enhance their understanding of, and participation in, PA and exercise. Furthermore, this study's findings will inform facility-based healthcare providers about the need to integrate health education on PA and pregnancy into antenatal and postnatal care visits in the setting.