In Barcelona, traffic was stopped as women took to the streets and set up road blocks.
Some 200 intercity trains out of 568 won't be operating, while 105 long-distance trains are cancelled, it said Wednesday.
The underground in Madrid will also be affected.
The 24-hour strike has been called by 10 unions. Feminist groups have also asked women not to spend money and to ditch their domestic chores for the day.
It kicked off at midnight with a demonstration in Madrid's Sol.
¡Aquí estamos las feministas! ¡Empieza la huelga compañeras ! https://t.co/0KEiUid81U— Madrid 8 de Marzo (@FeminismosMad) March 7, 2018
Across Spain, aprons were draped across balconies and appeared on statues armed with mops and toilet brushes.
Meanwhile Spain's two main unions -- the CCOO and UGT -- have called their members to stop work for two hours on Thursday.
All are campaigning against inequalities between men and women.
The upcoming strike has been the subject of much debate in Spain over the past weeks and many famous women have thrown their weight behind the stoppage.
Spanish star Penelope Cruz, for instance, has cancelled events she had planned and will also go on "domestic" strike, leaving her partner Javier Bardem to care for their two children.
But two of the five female ministers in Prime Minister Mariano Rajoy's government have said it would be better to observe a work-to-rule, in which employees do no more than the minimum required by the rules of their contract.
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