Abstract: This study examines how negative behaviours at work, like bullying and theft, impact employee performance. By reviewing previous research and conducting surveys, we found that such behaviours significantly lower job satisfaction, productivity, and increase the likelihood of employees wants to leave. The company’s culture and leadership can either mitigate or worsen these effects. To improve performance and create a healthier workplace, we recommend clear policies, regular training, and a supportive environment that discourages bad behaviour and promotes ethics. This study offers practical insights for managers and HR professionals to enhance employee well-being and organizational success.

Key words: Workplace deviant behaviour, Personality, Stress level, Work culture, Employee performance.

Downloads: | DOI: 10.17148/IARJSET.2025.124122