Ed Lynch's journey in Major League Baseball began when he was drafted by the Texas Rangers in the 22nd round of the 1977 amateur draft. However, it was with the New York Mets that Lynch would spend the majority of his playing career. He made his MLB debut with the Mets on August 31, 1980, stepping onto the mound as a right-handed pitcher. Over the next several years, Lynch became a reliable presence in the Mets' pitching rotation.

During his time with the Mets, Lynch was known for his control and ability to pitch effectively in various situations. He played a crucial role in the Mets' pitching staff throughout the early 1980s, a period when the team was building towards future success. His best season came in 1985 when he posted a 10-8 record with a 3.44 ERA, helping the Mets to a second-place finish in the National League East.

In 1986, Lynch was traded to the Chicago Cubs, where he continued to pitch until the end of his playing career in 1987. While his time with the Cubs was shorter, he provided veteran leadership and experience to the pitching staff. Over his career, Lynch compiled a 38-40 win-loss record, with a 4.00 ERA and 396 strikeouts.

After retiring as a player, Lynch transitioned into a front-office role, bringing his on-field experience to baseball management. He joined the Chicago Cubs' front office and eventually became the team's General Manager in 1994. In this role, Lynch was responsible for overseeing player transactions and team operations. He held the position until 2000, navigating the challenges of building a competitive team in the ever-evolving landscape of Major League Baseball.