The court ruled on Friday that the small girl was not abused and that the only way she might have had any sexual experience was during a filmed testimony after being coached by her father, late Drąsius Kedys.
An appeal against the ruling may be filed within 20 days.
Both the prosecutor and the defense lawyer asked the court to clear the defendant of the charges, while representatives of the children's rights watchdog suggested that the ruling note a lack of conclusive evidence to uphold the charges. The lawyer representing the girl asked to find Ūsas guilty.
The ruling in the case, which drew a heated public reaction, comes four years after the girl's father Drąsius Kedys filed a report to the police, accusing several people of sexualy abusing his daughter. He then allegedly went on to kill two of them, before going into hiding.
Kedys was found dead soon afterwards. Ūsas died in June 2010 in a traffic accident.
Prosecutors said charges were brought against some witnesses for pergury, but the court turned them down.
The case drew massive public attention. The little girl's aunt and Kedys' sister, Neringa Venckienė, founded a political party, the Path of Courage (Drąsos kelias in Lithuanian, a word play based on Drąsius Kedys' first name), which mobilized enough support around the platform of alleged corruption of Lithuania's justice system to get into parliament.