BOSTON (AP) _ Child World Inc. accused Toys 'R' Us of dirty pool Wednesday, saying the rival was slinking employees into Child World stores, buying promotional bargains and reselling some of the items in Toys 'R' Us stores.

Toys 'R' Us Inc. dismissed the accusations as a media ploy and claimed Child world has been guilty of the same behavior.

''When I got wind of this, frankly, I thought it was just an isolated manager and just in the Boston market, and then just in the Chicago market,'' said W. John Devine, chief executive officer of Child World, the No. 2 toy retailer behind Toys 'R' Us. ''We're getting reports now from every market in the country. This is an entire national scheme.''

Angela Bourdon, a company spokeswoman for Toys 'R' Us, said, ''This is purely a publicity stunt on their account.''

''We know they've done it with us,'' said Bourdon.

Child World charged Toys 'R' Us improperly took advantage of its ''Pandamoneyum'' promotion, intended to re-attract customers Child World lost during a financial restructuring late last year.

Under the promotion, customers receive coupons for all purchases that range from $5 off for buys of $25 up to $25 off for buys of $100. The certificates are redeemable in October.

Rules are posted in all Child World stores explaining that retailers do not qualify for the promotion, said Greg Miller, a Child World spokesman.

Child World said in a statement that some Toys 'R' Us employees and managers have been buying diapers and baby food and formula, sold at close to cost. They not only are getting the redeemable coupons, Child World said, but are ''reselling the Child World goods as Toys 'R' Us inventory.''

''We're talking here a million dollars or more of stuff that they are buying,'' said Devine. ''So they'll retrieve 25 percent or $250,000'' worth next month.

He said Child World store managers have caught Toys 'R' Us employees buying products.

''Some of them say I work for Toys 'R' Us, I guess you got me,'' said Devine. ''Some of them say they are not employed, when they are confronted. Then some of our managers will just cruise by Toys 'R' Us stores and find that the same people work for the company.''

A memo sent last week from a Dallas store manager to Child World's headquarters in Avon, Mass. said: ''We just had a TRU employee in doing a comp shop on our diapers and other items, and yes tried to purchase eight bags of diapers and 12 Ninja Turtles, totaling $116.20 before tax. This would have allowed them to receive the $25 Pandamoneyum certificate.''

Devine, who left Toys 'R' Us in 1983 after 17 years, said company attorneys were determining whether Child World had any legal options.

Bourdon of Toys 'R' Us denied that any employees were purchasing goods from Child World, and countercharged that the smaller chain has been guilty of such tactics.

Bourdon said Toys 'R' Us would wait to see what, if any, legal action Child World takes before commenting further.

Toys 'R' Us, with 458 stores, had $5.5 billion in sales last year, said Bourdon.

Child World, with 153 stores, lost $192.5 million in 1990, mostly due to restructuring costs, said Miller.