Ningyo Series began publication in Shounen Sunday Zoukan and later moved to Weekly Shounen Sunday. It was published sporadically during its serialization. The original Japanese release was two wideband volumes and was incomplete; the second was complete in three small size volumes.

The series was first published in English in the 1993 March issue of Animerica—Anime & Manga Monthly, a magazine published by VIZ Media. This magazine printed the first two story arcs of the first volume in Japanese. The remaining stories were subsequently published in comic book format by VIZ Select Comics, with 4 issues to each part, titled Mermaid Forest, Mermaid's Dream, Mermaid's Promise, Mermaid's Scar, Mermaid's Gaze and Mermaid's Mask, published from 1993 to 1995. The series was additionally printed in standard tankoubon format by VIZ Graphic Novels, who printed the series in three volumes, titled Mermaid Forest, Mermaid's Scar and Mermaid's Gaze, from December 6, 1994 to March 8, 1997. VIZ Media re-published the title as a four-volume series, this time as Mermaid Saga from July 14, 2004 to December 22, 2004, in the original right-to-left order. The series was also published in Argentina by LARP Editores as Cuentos de Sirenas from November 2008 to April 2009.