Subject: Formal Complaint Regarding Unprofessional Behavior of Co-Worker [Your Name] [Your Address] [City, State, ZIP] [Email Address] [Phone Number] [Date] [Recipient's Name] [Recipient's Position] [Company Name] [Company Address] [City, State, ZIP] Dear [Recipient's Name], I am writing this letter to officially file a formal complaint regarding the unprofessional behavior of a colleague, [Co-Worker's Name]. I feel compelled to bring this issue to your attention as it is negatively impacting both my work environment and productivity within the company. Firstly, allow me to provide a brief background about myself. I have been employed at [Company Name] for [duration] and have always strived to maintain a professional attitude and contribute to a harmonious work atmosphere. However, I have recently encountered several incidents involving [Co-Worker's Name]'s behavior towards me that are unacceptable and need immediate attention. The incidents I wish to draw your attention to include instances of constant disrespect, verbal abuse, and repeated attempts to undermine my credibility in front of colleagues and superiors. [Co-Worker's Name]'s derogatory remarks and offensive language have made it extremely difficult for me to concentrate on my duties and have created a hostile work environment. Despite my reasonable attempts to address the issue directly with [Co-Worker's Name], the behavior has persisted. I have also documented these incidents with dates, times, and descriptions for your reference, in case an internal investigation becomes necessary. This ongoing behavior makes it challenging for me to effectively fulfill my duties and has had a significant impact on my overall well-being. I firmly believe that a peaceful and respectful work environment is crucial for both personal and professional growth. Such behavior is detrimental to team dynamics and does not align with the values and principles that [Company Name] strives to uphold. Therefore, I kindly request that you take immediate action to investigate this matter thoroughly and take appropriate steps to address and resolve this issue. I trust in the company's commitment to promoting a healthy work environment and expect that appropriate measures will be taken to rectify the situation. In conclusion, I sincerely hope that this matter will be handled confidentially and expediently. I am confident that with your intervention, this issue can be resolved, and I can continue to contribute positively to the company. I am available for any further discussions or clarification, if needed. Thank you for your attention to this matter and for your swift resolution. Yours sincerely, [Your Name]