Healthcare waste which consists of waste materials generated at healthcare facilities is hazardous to both the environment and human life. However, many people are unaware of the dangers of medical wastes. Previous studies have neglected the assessment of the level of awareness and attitude of health workers toward healthcare waste. Therefore, this study assesses the level of awareness of healthcare workers about the dangers and their attitude toward the waste and its implications. The study, which employed cross-sectional design with 334 participants, was conducted in Southeast Nigeria. Data collection was through questionnaire and in-depth interview guide. Data analyzed through descriptive statistics revealed that the level of awareness of health workers about the dangers of healthcare waste is high; their attitude toward healthcare waste is poor; and that the consequences of mismanaged healthcare waste are devastating. Therefore, healthcare facilities should have a functional waste management policy, train their staff on ways of handling waste and educate the public about dangers of healthcare waste. Assessment of the level of awareness of healthcare workers about healthcare waste, their attitude toward healthcare waste and the consequences of healthcare waste for healthcare workers and others at healthcare facilities in Southeast NigeriaHealthcare waste which is made up of waste materials generated at healthcare facilities during diagnosis, patients review and/or treatment are hazardous. Despite these dangers posed by healthcare waste, in Nigeria, many people are unaware that medical wastes are potentially dangerous. Again, most studies on healthcare waste had been carried out outside Nigeria. The few studies in Nigeria did not assess the level of awareness and consequent attitude of health workers toward healthcare waste. Therefore, this study assessed the level of awareness of healthcare workers about the dangers of healthcare waste, their attitude toward this waste and the consequences of poorly managed healthcare waste. The study which employed cross-sectional design, using 334 participants selected through multi-staged sampling, was conducted in Southeast Nigeria. Data were collected using questionnaire and in-depth interview guide. Data analyzed through descriptive statistics revealed that the level of awareness of health workers about dangers of healthcare waste is high but their attitude toward healthcare waste is poor. The implications of this is that lives of the healthcare staff, patients, hospital visitors and the public are not safe especially in this era of COVID-19 pandemic. As a result, we conclude that healthcare facilities should have functional waste management policy, train their staff on appropriate ways of handling waste and educate the public about dangers of healthcare waste. However, the study focused only on social issues about healthcare waste management. We did not assess technical/engineering factors involved in healthcare waste management as well as the views of patients.