Alvargonzález made the remarks on Thursday at a NATO summit in Wales, where Us president Barack Obama is expected to ask for allies in possible military intervention against Isis terrorists in Iraq.
"In the minds of the Spanish people the issue of Iraq is, as you know, complicated," he was quoted as saying in Spanish daily El Mundo.
"We'll see where we get to but I don't think we'll go down the military route for now. There are other countries prepared to do that," he added.
Denmark, meanwhile, is to send a Hercules aircraft and up to 55 military personnel to transport weapons and other military supplies to Iraq as its contribution to the international campaign against jihadist militants in the north of the country.
Alvargonzález did not eliminate the possibility of Spanish military involvement at a later date, saying: "It's too soon to make a definitive decision."
"Let's wait and see what's on the table."
Spain's involvement in the Second Gulf War was a hugely contentious issue in domestic politics and had a major bearing on the results of the country's 2004 general elections.
A terrorist attack in Madrid on March 11th, 2004, just three days before Spanish voters went to the polls, killed a total of 191 people on two packed commuter trains.
Spain's conservative Popular Party government of the time initially blamed the attacks on the Basque separatist group ETA. But many Spaniards believed they were trying to deflect attention from a possible link between the bombings and Spain's involvement in the Iraq War.
The Popular Party lost the general elections and a socialist PSOE government took power, subsequently withdrawing Spanish troops from Iraq.
Current PSOE leader Pedro Sánchez echoed Zapatero's remarks this morning and declared that he would not send troops to Iraq or Syria in the event of becoming prime minister.
Speaking to Europa Press he said Spain should "of course" get involved by sending humanitarian aid "to the civilian population who are being punished an annihilated by ISIS."
But he underlined that it would be "not by sending troops to either Iraq or Syria".