One of the four suspects is suspected of murder, while the other three are suspected of being accessories to murder, according to a statement from police.
The men were arrested without incident during a Tuesday morning police raid in Södertäjle, south of Stockholm.
The men are known by police for previously criminal activities, but had not previously been targeted by police investigating the murder of the Moussa brothers.
"We've had a short interrogation with the men in which they were informed of the criminal suspicions against them. I don't want to comment on their view of the suspicions," county police spokesperson Ulf Göranzon told the TT news agency.
The 26-year-old Moussa was and his 40-year-old brother Yaacoub were shot dead in Café Oasen, a known gambling club in Södertälje's Ronna shopping precinct on July 1st of this year.
According to witnesses, three men came into the premises shortly after 2am in the morning and began firing automatic weapons, killing the two brothers and injuring a third victim.
At the time, police suspected the killings may have been a targeted killing orchestrated by elements of the criminal underworld.
Göranzon wouldn't elaborate on possible motives for the killings or comment further on what specific roles the men may have had in the shooting.
Eddie Mousssa was a promising young football star of Lebanese-Assyrian extraction who held both Swedish and Dominican passports. He debuted for Assyriska FF, a Södertälje-based club which played one season in Sweden's Allsvenskan top-flight after winning promotion in 2004.
The club, which was founded only in 1974, has a large following in Södertälje and is considered by many to be a substitute national team for the Assyrian people.