Where did the Elves go after the Helm's deep battle in LOTR?

The Elves at Helm's Deep were a departure from the book version and were added for some reason by Peter Jackson and his team.

Because of this, they would need to play a bigger part in an already pretty expansive story or they would have to be quietly dropped from the plot.

Perhaps they filmed a few scenes either about them getting wiped out or going home, but it seems that they were simply dropped in the hope that nobody would notice.

Just to be clear, I am currently watching the extended/special edition of The Two Towers. So the main reason the elves, if any survived, did not ride out with Aragorn and Theoden, simply put, they didn't have enough horses left. You must remember that the elves arrived on foot not on horseback. It would be safe to believe that any remaining elves stayed in the keep to protect the entrance to the caves. Then when the forest finished off the Uruks they could safely return their own forest to help defend their home. This is of course all educated guesswork of an old Tolkien fan that only pertains to the movie, since as was already pointed out in the book the elves were never at Helms Deep.

I think we can safely assume that all the Elves died during the fight. They took the full brunt of the Urak-hai army on the ground after the wall was destroyed.

Let's not forget, that their commander (the only Elf who could have issued a retreat) was Haldir - and he died.

The Elves are fiercely well trained and proud fighters, it is no surprise at all that they fought til death, instead of retreating to the keep.

In the book, the elves from Lothlorien were not involved in this battle. A few days after the battle of Helm's Deep, orcs from Dol Guldur swarmed into the forest of Lothlorien in a full-scale assault. They were repulsed by the power of the elves and Galadriel’s ring.

I assume that in the movie, elves who survived the battle of Helm's Deep, immediately returned to Lothlorien to defend their forest.

well in the movie i could see some elves running trough this round arch door thing and then towards an entrance so i just assume they left helmsdeep after the battle (Not filmed) to go to valinor or where all the elfs went when they left these middle earth lands. :) but thats how i just like to see the end of the elfs.....

All of the elves that went to Helm's Deep were killed in the battle. The last shot where any elves are seen is when the Uruk-Hai breach the main gate and begin flooding into the inner courtyard as Aragorn and Theoden try to get as many men as they can into the throne room. No elves are seen running into the Throne room and the next shot of helms deep shows that the Uruk-Hai have complete control of the Castle and are trying to breach the throne room implying that all defenders outside the room have been killed.