The air tightness of buildings has the greatest potential for energy savings. Reduced fresh air intake raises concerns about natural ventilation systems and the need to provide users with a comfortable indoor climate. The pace at which heat is expelled from a building's interior surfaces increases with vent size, putting residents' health at risk and causing discomfort. The study aimed to evaluate critical factors that contribute to poor natural ventilation in residential buildings, and its associated effects. A quantitative research approach was adopted using purposive sampling for data collection due to undefined residential buildings. 215 questionnaires were distributed to occupants of residential buildings within six (6) selected communities within the Atwima Nwabiagya Municipality. 210 completed questionnaires were collected and analyzed using mean and relative importance index (RII) score ranking. From the findings, nineteen (19) identified variables categorized into three (3) main factors contribute to poor natural ventilation of residential buildings. The most critical factor is unplanned building design and usage with an average RII of (0.955). Most privately owned residential buildings were built with no professional consultation aiming to avoiding professional cost. Eleven (11) variables grouped under four (4) main effects were identified as effects associated with poor natural ventilation, the top-ranked ranked effects were Health risk with an average RII of 0.930. Good natural ventilation is a determinant factor for sustaining occupants’ satisfaction and wellbeing. Therefore, it was recommended that purpose of room space should be well defined before its design and construction. Public education on the need to engage experienced professionals in design and construction should be intensified. The paper affirms to the relevance of natural ventilation for occupants in residential buildings; also, usefulness to engage construction professionals and clients.