Eleven civilian casualties, including one death and multiple leg amputations, were recorded from mines by the rights group.
Ukraine has been urged to stop using banned landmines by a rights group.
Human Rights Watch (HRW) said it had uncovered new evidence that Ukrainian forces had deployed the indiscriminate weapon as they battle the Russian invasion.
The international NGO documented 11 civilian causalities, including one death and multiple leg amputations, from "petal" or "butterfly" mines, which it claimed Ukraine had fired by rocket into Russian-occupied territory near the eastern city of Izium last year.
In a statement released on Friday, it said Russian forces have also used at least 13 types of antipersonnel mines across Ukraine since the start of its invasion in February 2022, killing and maiming civilians.
Landmines can inflict a devastating toll on civilian populations long after a conflict ends. The PFM-1 antipersonnel mines, which HRW reported Ukraine launched into Russian-controlled areas, are small plastic blast mines, which detonate when pressure is applied - for instance, if someone steps on it.
HRW called on Kyiv not to employ the banned weapons, investigate their suspected use and hold accountable those responsible.
“A prompt, transparent, and thorough inquiry could have far-reaching benefits for Ukrainians both now and for future generations,” said Steve Goose, arms director at Human Rights Watch.
“Ukrainian authorities concerned for their civilians’ protection have an interest in getting to the bottom of how, when, and where these mines were used,” he added. “And doing all they can to stop them from being used again.”
Ukrainian officials said they would look into this issue when HRW first reported on it in January.
The US-based group says it has shared its most recent findings with the Ukrainian government, but received no response.
HRW has published four reports documenting the use of landmines by Russian forces, which it said "violates international humanitarian law".
Moscow has not joined the 1997 Mine Ban Treaty that outlaws landmines due to their inherently discriminatory nature. Nor has the United States.
Ukraine ratified the treaty in 2005, which also requires countries to destroy their stocks of mines, clear mined areas and provide assistance to victims.