She was the amicus curiae in the landmark case of Bangladesh National Women Lawyers Association (BNWLW) v. Bangladesh, in which the Supreme Court supported the judicial practice of referring to international human rights law in the absence of domestic legislation.

She also worked on a multi-country study on honour crimes with the Centre for Islamic and Middle Eastern Law at SOAS.

[9] In July 2018, the United Nations Human Rights Council appointed Hossain to co-chair (alongside David Crane and Kaari Betty Murungi) a three-person Commission of Inquiry into the killing of at least 140 Palestinians by the Israeli army.

[11] In 2022, she was appointed as the chair of the UN fact finding mission on violence against women during the 2022 Iran protests.

[12] Apart from BLAST, Hossain is a member of the Executive Committee of the Dhaka-based human rights organisation Ain o Salish Kendra.