The delegation from the Organization for Security and Cooperation in Europe held a news conference in Kiev and blasted what it said was a concerted government effort to intimidate opposition candidates and swing the vote in its favor.
"Democratic progress appears to have reversed in Ukraine," said Walburga Habsburg Douglas, leader of OSCE's group of short-term observers.
Delegation member Andreas Gross added: "Ukrainians deserved better from these elections. Citizens lost their ownership of the election process, as well as their trust in it."
The lack of trust seemed to have resulted in a record low turnout for the voting of nearly 58 percent. The Washington Post said that as a precaution, a judge Monday issued a two-week ban on outdoor protests.
The Kiev Post said while opposition parties seemed to be holding their own at the national level, local offices were going heavily toward candidates from the ruling Party of Regions. The ruling party is also expected to control the Parliament.