The two men, who were both 39, spent Saturday night in their local bar in Vllaluenga de la Vega in Palencia, Castilla y Leon, challenging each other to see who could consume more alcohol.
After spending the afternoon and evening drinking beer and chasing it down with whisky shots, the two inebriated men stumbled home to the house they shared with five others and passed out in their living room. They reportedly consumed at least two whisky bottles between them.
They were both discovered dead by their five other housemates in the early hours of Sunday morning.
The five were then arrested by police facing charges of failing to come to the rescue of someone in peril. They were suspected of being involved in the drinking game and not seeking help for their friends after they became dangerously drunk.
The group reportedly told investigators that they typically played drinking games and when someone passed out, they would leave them lying on their side in the living room so as to avoid them choking on their vomit.
The men have been released without bail after giving statements to an investigating magistrate.
The men, who were Romanian, worked together at the local timber factory, reported El Mundo and were integrated and well-liked in the village, according to local mayor Raúl Berzosa.