This study explores the impact of perceived work culture on employee performance within the business process outsourcing (BPO) sector in the city of Manila, focusing specifically on the influence of bullying, harassment, discrimination, and negative leadership. Using the lens of Social Exchange Theory (SET), the research investigates how these workplace behaviors affect employee productivity, morale, and organizational commitment. A descriptive-correlational research design was employed, with data gathered from 353 employees in one of the leading BPO companies in Metro Manila selected through simple random sampling. A structured questionnaire measured perceptions vi of workplace culture and employee performance. Statistical tools such as weighted mean, standard deviation, and multiple linear regression were used to analyze the data. Reliability tests confirmed strong internal consistency across all constructs. Findings reveal that while employees generally disagreed with the presence of severe workplace bullying and harassment, subtle forms of toxicity, particularly negative leadership, remain prevalent and significantly affect performance. Cultural values like hiya (shame) and pakikisama (harmonious relationships) were identified as barriers to reporting workplace mistreatment. Among the factors studied, negative leadership showed the strongest adverse effect on employee productivity and well-being. The study concludes that toxic workplace culture negatively influences employee engagement and organizational effectiveness. It recommends the implementation of inclusive leadership development programs, confidential reporting mechanisms, and stronger anti-bullying and harassment policies. The insights provided are valuable for HR practitioners, organizational leaders, and policymakers aiming to foster healthier and more productive work environments in the Philippine BPO industry.