Herrero Lázaro was born in Sando de Santa Maria, Salamanca, Castile and León, Spain on 28 December 1913. He lived much of his life in Ciudad Rodrigo, a city in Salamanca near the Spain-Portugal border, before moving to the capital. He married Inés García García, who passed away around 2007, and had three children. He worked for the Ministry of Public Works as a conservation manager.

At the time of his 100th birthday, Herrero Lázaro was said to be in very good health for his age, and was still able to go shopping and take bus rides on his own. He enjoyed drinking espressos and wine, and read the newspaper daily. He kept abreast of current affairs, including politics and sports.

Herrero Lázaro passed away in Salamanca, Spain, on 29 December 2023, one day after his 110th birthday.