Discrimination within the workplace negatively impacts employees across the board. Over the past decades, workplace discrimination has been studied in various fields, such as wage-earning workplaces, healthcare, and social media. However, considerable work is still needed to gain a deeper understanding of workplace discrimination in Software Engineering. Objective: The overarching research objective is to gain deeper insights into the causes, forms, and effects of workplace discrimination toward software professionals, thus providing implications to various stakeholders to reduce workplace discrimination. Method: We applied an empirical investigation to reach our goal. We collected 97 complete responses from our online survey, including a set of open-ended, close-ended, and scale questions. Results: We observed that age, gender, and race are the major causes among software professionals who have experienced or witnessed workplace discrimination. In addition, our study reveals that female professionals are more prone to experience discriminatory actions compared with male professionals. Furthermore, we found that most discriminatory actions happened more than one time, and most of the actions are carried out by colleagues in daily work, causing negative mental and physical effects. Conclusion: This paper provides an understanding of the causes, forms, and effects of workplace discrimination and discusses concrete suggestions to help reduce workplace discrimination in the software engineering field.