Despite the high demand for skilled engineers, retention and completion rates in engineering programs remain alarmingly low. Many students leave before graduation due to a combination of academic, institutional, and personal challenges. Why are they leaving engineering education and/or not entering the engineering workforce? The literature suggests teaching and learning play a large role in these extreme attrition rates. Factors such as rigorous coursework, inadequate preparation in foundational subjects, lack of engagement, and limited support systems contribute to high attrition rates. Additionally, underrepresented groups, including women and minorities, face unique barriers that further hinder persistence in engineering fields. This chapter provides an overview of the well-documented poor retention rates and lack of diversity in engineering education programs and the engineering workforce, and concludes by providing motivation to improve teaching practices within engineering.