Protesters threw stones and set off fireworks near Taksim Square – a traditional rallying point for left-wing protesters.
Turkish police used rubber bullets and tear gas. Twenty-four people, including six policemen, were wounded in the clashes.
Opponents of President Recep Tayyip Erdogan have accused him of repressive tactics ahead of elections in June.
The May Day rally was the first major protest since the Turkish parliament passed a controversial law giving police increased powers in March.
The law widens powers to conduct stop-and-search and detain demonstrators. Much of Istanbul’s public transport had been shut down because of security concerns.
The government had said Taksim Square would only be open to those who came peacefully, not for “illegal demonstrations”.
While Istanbul police said nearly 140 people were detained, activists said the number was nearly double that.
Taksim Square was at the centre of nationwide anti-government protests for weeks in 2013.
On May 1st, tens of thousands of people also held a peaceful march in the capital Ankara.
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