The 264-strong clothing and accessories chain, which caters for women aged over 50, hopes to cash in on Britain's ageing population and recovering consumer spending by expanding its footprint and range of products.
Owners Sun European Partners are expected to sell around £50 million of shares to institutions to give the retailer a market value of up to £130m. Bonmarche was bought by Sun European Partners in January 2012 for a reported £10m after its former owner Peacocks plunged into administration.
But the Wakefield-based chain, which opened its first store in Doncaster in 1985, said it had since been transformed, with like-for-like sales surging almost 13% over the past six months and a "step change in profitability".
Bonmarche plans to expand at garden centres across the UK, on cruise ships and also has tie-ups with around 1000 care homes, where staff hold sales events on the premises.
The chain also has a mail order arm, phone ordering service and TV shopping channel, and around 6.5 million women are signed up to its loyalty programme.
The flotation will raise money for its owners rather than the company, and will mean at least 40% of its shares are traded on the Alternative Investment Market (AIM).
Management hold almost 8% and are not selling down their stake. Chief executive Beth Butterwick said: "The success and strong financial performance enjoyed by the business over the last 18 months, coupled with our exciting growth strategy, makes this is an opportune time to bring the company to AIM.
"We are confident that our competitive position and loyal customer base means that we are well placed to capitalise on this attractive and fast-growing niche of the retail sector."
Bonmarche earned underlying profits of £9.1m on revenues of £146.8m in the year to the end of March.