This time, the mood will be more courteous though without any major breakthroughs, say diplomats.
One EU diplomat said Brussels had been cautiously impressed by a series of moderate speeches by Medvedev.
"It is a new president in a new position with his ambitions and we need to find out how he wants to implement these policy aims," said the diplomat, referring to promises by Medvedev to fight corruption and enhance the rule of law.
Medvedev told Reuters in an interview earlier this week he wanted to seal a "serious" pact with the EU and that his country was a "major European state ... which defines itself as part of Europe".
But drafting a pact on which both Moscow and Brussels can agree is likely to be an arduous process.
The EU wants more access for its firms to Russia's energy sector, saying that is key to security of supply. Russia is reluctant to offer that and is making a counter-demand for better access for its companies to European markets.
There are differences too over human rights, trade, and rival interpretations of Europe's turbulent history.
EU leaders are also expected to use the summit to restate their concerns that Russia's support for a separatist region of Georgia is stoking tension in the former Soviet republic.
Even before the two sides tackle the substance of their pact, there is no consensus on the form the document will take.
Kremlin foreign policy adviser Sergei Prikhodko said Russia wants a brief, legally binding pact followed by a string of more detailed agreements.
The EU side has been non-committal about what sort of document it wants to see. EU Ambassador to Moscow, Marc Franco, said on this issue he was "confident that a consensus could be reached during the summit".
