Deepak Kalpoe, 24, left the lockup in the afternoon and got into a car with one of his attorneys. His 21-year-old brother Satish, who was released earlier in the day, declined to speak to reporters when his attorneys dropped him off at his house.
A third suspect, Joran van der Sloot, remains in jail. He and the two brothers were the last known people to see Holloway before she vanished more than two years ago, hours before she was scheduled to return home to Alabama with fellow high school classmates celebrating their graduation.
All three have denied any role in the disappearance of Holloway, who has not been seen since she left a bar with the suspects May 30, 2005. She was 18 at the time.
No trace of Holloway has been found despite extensive searches, and prosecutors say they have evidence that she is dead.
The three suspects were re-arrested Nov. 21 on suspicion of involvement in Holloway's death, and authorities spoke of "new incriminating evidence" suggesting the men were involved in covering up a crime or disposing of a corpse.
But defense attorneys complained that the new material was little more than misunderstandings in the suspects' recorded conversations.
On Friday a judge ruled the evidence was not strong enough to continue holding the Kalpoes, and ordered them released.
Aruba chief prosecutor Hans Mos called the decision a setback, but said the investigation will proceed.
"We had hoped for a longer period to confront these suspects with the material we have against them," he said. "We were not finished with that yet. But this is the way the law says it has to go."