Black Jack ONA is a oNA (web) anime that premiered in winter 2001.

About the production: there are 12 episodes of about 16 minutes and its current status is "finished".

Its main genres are drama, with themes such as Kids, Work and Medicine.

On AniList, Black Jack ONA has an average score of 58%, an average score, and appears on 957 users' lists.

Black Jack, a mysterious young unlicensed doctor with godlike skills, travels the world performing feats of impossible surgery, charging vast fees for his services, and challenging the corrupt practices of the medical establishment. This selection of stories, each adapted from a single original manga issue, focuses more on interpersonal relationships and back-story than most other Black Jack series. (Source: Anime News Network)

Official synopsis from AniList.