Victoria Alcock (Julie Saunders), Kika Mirylees (Julie Johnston) and Helen Fraser (Sylvia 'Bodybag' Hollamby) are the only characters to remain through the entire series run.
Linda Henry (Yvonne Atkins), Luisa Bradshaw-White (Lorna Rose), Kellie Bright (Cassie Tyler) and Annette Badland (Angela Robbins) all went on to play members of the Carter family in 'EastEnders'.
Jack Ellis originally left Bad Girls in the final episode of the sixth series when justice finally caught up with his character, Jim Fenner. However, Shed Productions persuaded Ellis to sign on for one further series and Fenner came back in the first episode of the following series.
Ratings dropped during Series 1, meaning that Series 2 was nearly not commissioned.
There was never any explanation as to why some characters never returned to the series. These include: Di Barker, Colin Hedges, Seleena Geeson, Kris Yates, Darlene Cake, Arun Parmer and Kevin Spiers.