It is not known yet whether or not Mugabe has retained the presidency.
Utoile Silaigwana, the deputy chief elections officer, declared the results in a nationwide radio and television broadcasts.
He went off the air saying: "We'll be back with you when we have more results."
The election commission had said the delay was due to presidential and parliamentary elections being held at the same time, but the piecemeal announcement has left observers questioning the transparency of the process.
Some election observers have said that initial results were known by 11pm (2100 GMT) on Saturday night, just four hours after polls closed.
In previous elections, partial results have been announced within hours of voting ending.
The MDC won the first seat to be declared, in a new constituency called Chegutu West, which is about 100km west of the capital, Harare.
A total of 210 parliamentary seats are due to be declared.
The opposition has already claimed victory in the vote that posed the biggest threat ever to Mugabe's 28-year rule.