Vlasios Maras fell off the horizontal bar on Saturday at the Beijing Games in another Greek tragedy for the former two-time world champion on the apparatus, dpa reported.
Maras scored a low 13.975 points in the qualifying round which gives him no hope of making the final in his best event.
The disaster comes four years after he also missed the high bar final at his home Games in Athens because of low marks.
I wanted to make a perfect routine, but something went wrong. It was unbelievable, it happened so fast," said Maras after his hand slipped off the bar and he fell to the ground.
Maras said he was still hoping to make the final of the all-around event with good results on the other apparatuses.