Edwin Rosario has six losses against six opponents on his boxing record. For a list of Rosario's best fights, refer to "Best fights of Edwin Rosario".
On January 30, 1993 Edwin Rosario faced off against Frankie Randall at age 29. He was coming in with a record of 42-6 (37), and Randall was 31 years old and with a record of 45-2-1 (36). Rosario lost the fight via 7th-round TKO.
On April 10, 1992 Edwin Rosario met Akinobu Hiranaka in a super-lightweight (WBA) world-title defense fight. Rosario was 29 years old and with a record of 41-5 (36). Rosario lost the fight via 1st-round TKO and lost the title.
On April 4, 1990 Edwin Rosario met Juan Nazario in a lightweight (WBA) world-title defense fight. Rosario was 27 years old and with a record of 39-4 (35), and Nazario was 26 years old and with a record of 21-2 (15). Rosario lost the fight via 8th-round retirement and lost the title.
On November 21, 1987 Edwin Rosario met Julio César Chávez in a lightweight (WBA) world-title defense fight. Rosario was 24 years old and with a record of 31-3 (27), and Chávez was 25 years old and with a record of 56-0 (45). Rosario lost the fight via 11th-round TKO and lost the title.
On June 13, 1986 Edwin Rosario fought Hector Camacho in a lightweight world-title fight for Camacho's WBC title. Rosario was 23 years old and with a record of 28-2 (24), and Camacho was 24 years old and with a record of 28-0 (15). Rosario lost the fight via 12-round split decision.
On November 3, 1984 Edwin Rosario met José Luis Ramírez in a lightweight (WBC) world-title defense fight. Rosario was 21 years old and with a record of 24-1 (21), and Ramírez was 25 years old and with a record of 87-5 (73). Rosario lost the fight via 4th-round TKO and lost the title.
