The result led his main political opponents to call for another vote to prevent a national crisis.
Venezuela's National Election Council announced that Maduro won nearly 68 percent of the votes Sunday. It said he defeated Henri Falcon by more than 40 points.
Falcon accused the Maduro government of buying votes and dirty tricks to increase the number of poor Venezuelans voting. Falcon refused to recognize the results, and said the election "lacks legitimacy." Falcon told supporters that he will fight on instead of joining others in exile.
Third-place finisher Javier Bertucci agreed on the need for new elections. Venezuelan officials say Bertucci won around 11 percent of the vote. He urged the president against being a candidate in a re-vote. Bertucci warned that if Maduro pressed forward, Venezuela would explode before his new six-year term begins in January.
Maduro's disputed victory is likely to raise international pressure on the Venezuelan leader. On Monday, the United States government announced economic sanctions to punish Venezuela for what officials called its "fraudulent" election. President Donald Trump signed an order that bars Americans from dealing with Venezuela's oil industry.
The European Union and some Latin American countries also warned that the presidential election was not fair.
Chilean president Sebastian Pinera, said, "Venezuela's elections do not meet minimum standards of true democracy." He added that, "Chile does not recognize these elections." Panama's government also said it would not recognize the results.
But Cuba and El Salvador, two allies of Venezuela, sent their congratulations on the vote.
Venezuela's economic crisis
Maduro called for discussions with his defeated opponents, but he showed no sign of wanting new elections. He told supporters, "It doesn't faze me when they say I'm a dictator."
The Venezuelan leader promised to repair an economy he says has been damaged by Colombia and the U.S.
In the past two years, more than 1 million Venezuelans have fled to neighboring countries as the value of the national currency dropped.
Venezuela's oil production — the source of almost all of its overseas earnings — has collapsed to its lowest level. And U.S. government sanctions have made it impossible for Venezuela to renegotiate its debts.
I'm Jonathan Evans.