Gabriel Montenegro Gutiérrez was born in Santa Ana, El Salvador to Gabriel Montenegro Soberón, a Guatemalan immigrant, and Eva Gutiérrez from Santa Ana, El Salvador.
The former was the eldest son of Dr. Manuel Palomo Cuellar, one of the founders of the Salvadoran Red Cruz, and Angela Trabanino González.
Angela was the eldest daughter of José Antonio González Portillo, the mayor of Santa Tecla, El Salvador who served several terms.
José Antonio was the right hand of his brother, Santiago González Portillo, President of El Salvador (15 April 1871 – 1 February 1876), and, the later, María Elda Salazar Iraheta, a first cousin of the famous Salvadoran artists Salarrue and Toño Salazar, since she was a daughter Estaban Salazar Angulo and Matilde Iraheta, a daughter of the Salvadoran War Hero, General Francisco Iraheta Larreta.
After completing his formative years in El Salvador, He continued his education in Purdue University.