Rivas was born on October 12, 1924, in Puerto de Ocoz, Guatemala, where his parents were vacationing.
While living in Spain he studied literature and philosophy at the Universidad Complutense de Madrid and wrote a couple of pieces that were published in "Alferez", a Spanish magazine that also published works by Julio Ycaza Tigerino and Pablo Antonio Cuadra.
There he published his most famous work, a book of poems titled "La insurrección solitaria" ("The solitary insurrection".)
In this capacity he lived in Los Angeles, Paris, San José, Costa Rica and again in Madrid.
After his diplomatic career, Martinez Rivas worked as a professor at the Universidad Nacional Autónoma de Nicaragua.