The Zimbabwe Electoral Commission said that Mugabe's Zanu-PF party had won 142 seats in the 210-seat chamber.
The result, according to analysts, is enough for Zanu-PF to change the constitution. But the results in the presidential race were yet to be announced.
Mugabe's main rival Prime Minister Morgan Tsvangirai has already dismissed the election as "a sham".
Tsvangirai, who heads the Movement for Democratic Change (MDC) and is running for president against Mugabe, said the vote had been a "huge farce".
Though a local monitoring group also said that the poll was "seriously compromised", the two main observer groups broadly endorsed the election, saying it was free and peaceful.
Zanu-PF and the MDC have formed an uneasy coalition government since 2009, in a deal which ended deadly violence, erupted after a disputed presidential poll the previous year.