Three of the Bahrainis have already served over half their jail sentence while the case was underway.
However, another Bahraini and a Qatari are yet to be arrested and are presumed to be at large overseas.
One of the Bahrainis already in custody admitted that he went to Afghanistan to fight alongside the Taliban against coalition forces.
He was arrested on August 2 after arriving in Bahrain from Iran and was accused of receiving weapons and explosives training, carrying out terrorist attacks overseas and funding terrorism.
The 22-year-old, from Umm Al Hassam, admitted he was in Afghanistan for jihad, but denied that he was a terrorist.
Two other Bahrainis also in custody, aged 38 and 40, were accused of funding terrorism overseas and arranging travel for fighters going to Afghanistan.
Defence lawyer Abdulla Hashim said he expected the three men to be released soon.
"The defendants’ acts do not show that they belong to any foreign (terrorist) organisation or took part in any military operation against a foreign country abroad," Mr Hashim told the GDN after the verdict was announced.
"The six-month jail sentence is nothing and we consider this to be an acquittal.
"The defendants have already spent almost six months in custody and I believe that they will be released soon."
However, he said he did not expect this to be the last terrorism trial and expects the US to frown upon the verdict.
"I believe that we will witness many similar cases in future and that is simply to please foreign powers," he said.
"We invite those responsible in this country to avoid pushing youths into a corner, because this may lead to violent reactions.
"We also believe that the ruling delivered by the court will not please many sides and personalities," said Mr Hashim, who later clarified that he was referring to the US.
The fourth Bahraini defendant and the Qatari were jailed for six months in their absence yesterday.
The Bahraini yet to be arrested was also accused of receiving weapons and explosives training, carrying out terrorist attacks overseas and funding terrorism, while the Qatari is accused of providing financial support.
However, Mr Hashim said he did not know on which charges the five men had been found guilty.
Defence lawyer Fareed Ghazi, representing the 22-year-old Bahraini, had earlier said he first tried to travel to Iraq to join insurgents there after he saw how prisoners were treated at Abu Ghraib.
However, he was arrested as he tried to enter Iraq through Syria and was jailed for a month-and-a-half.
After returning to Bahrain he decided to travel to Afghanistan where he was due to receive weapons training, the court heard.
However, Mr Ghazi said he did not do well in the training and had to return to Bahrain because he fell sick.
