Called by 10 unions to demand gender equality, particularly where salaries are concerned, the strike dominated the headlines with famous female presenters noticeably absent from radio or television shows.
Feminist groups have also called on women not to spend money, particularly on items such as deodorant whose versions created for women often cost more, and to ditch domestic chores for the day.
The strike is attempting to emulate Iceland's 1975 work stoppage, when women took a day off in October to demonstrate their vital contribution to the country's economy and society.
However, Spain's two main unions - the CCOO and UGT - have called on their members to stop work for only two hours on Thursday.
Ana Reyes, a 37-year-old PR executive, said she was striking "in the hope that the importance of half of the population will be recognized and that it will bring about a real change."
The strike comes as countries around the world mobilize for #internationalwomensday2018, a worldwide trending topic on Twitter, and comes hot on the heels of #MeToo and #Timesup campaigns that went global with allegations of sexual misconduct in Hollywood.
Spain is a leading country in the fight for women's rights and against gender violence, even though much remains to be done.
In 2004, for instance, the then Socialist government approved a law on violence against women that the European Council has upheld as an example to follow.
The groundbreaking legislation set up a hotline that would not appear on users' phone bills, offered free legal aid and established special courts for victims.