Despite the widespread problem, Asia has been slow to enact reforms to protect domestic workers, the US-based rights body said along with the International Domestic Workers Network (IDWN) and the International Trade Union Confederation (ITUC).
The groups released a new report assessing progress since the 2011 adoption of the Domestic Workers Convention, a treaty entitling domestic workers to the same basic rights as other workers.
"Domestic workers from India, Nepal, Sri Lanka, Indonesia and Cambodia experience horrific abuses," said Nisha Varia, a senior rights researcher at Human Rights Watch.
"These governments should pick up the pace of reform to introduce long overdue protections for both domestic workers at home and those migrating abroad."
More than 25 countries have improved legal protections for domestic workers, with many of the strongest reforms in Latin America.
The Philippines is the only Asian country to have ratified the Domestic Workers Convention.
The 33-page report, "Claiming Rights: Domestic Workers' Movements and Global Advances for Labor Reform," was released at an Oct 26-28 meeting of labour leaders from more than 40 countries in Montevideo.
As Human Rights Watch, IDWN and the ITUC have documented, many domestic workers in Asia and those migrating from Asia to the Middle East experience a wide range of abuses.
These include unpaid wages, restrictions on leaving the households where they work, and excessive work hours with no rest days.
Some may face psychological, physical or sexual abuse and can get trapped in situations of forced labour, including trafficking.
There are an estimated 53 million domestic workers worldwide, the majority of them women and girls, and many of them migrants.
Recent International Labour Organization (ILO) research found that while child labour in other sectors has declined in recent years, child domestic labour increased by nine percent between 2008 and 2012.
In Asia, the region's domestic workers, trade unions and migrants' rights groups have focused on building awareness and political will to lay the groundwork for future ratifications.
The most active dialogue is taking place in Indonesia, India and Nepal. The report notes incremental reforms in India, Singapore and Thailand.
India extended a health insurance scheme to domestic workers in May 2012 and included them in a 2013 law prohibiting workplace sexual harassment.