Republican Arthur A. Fletcher, calling current city juvenile and criminal justice programs a misguided "patchwork quilt" of failing efforts, promised yesterday an "all-out attack on crime and juvenile delinquency" if he is elected mayor in the Nov. 7 general election

In the first major speech of his campaign against Democrat Marion Barry and two others, Fletcher painted a portrait of a city where juveniles repeatedly commit "serious crimes" with little fear of reprisal, where little rehabilitation of offenders occurs, and where an abundance of anti-crime paraphanelia has turned some neighorhoods into "caged" societies.

Calling himself "a family man" concerned with an apparent breakdown in old-fashioned discipline, Fletcher asked more than 100 Republican women during a luncheon speech at the Mayflower Hotel to help "send the youth of the District of Columbia a clear message."

"They must be told and shown that it takes fewer brains and even less guts to sniff 'coke' and 'shoot up,'" he said, "than it does to maintain self-discipline and self-respect and become self-reliant despite the obstacles.

"They must be told and shown the benefits of listening to their parents and teachers as much as they listen to the words of radio disc jockeys and pop singers.

"They must be told and shown the benefits to be gained to learn to read and write as well as memorizing the words and dances to the current disco tunes."

Fletcher's "firm enforcement" pitch on juvenile crime and his comparison of what he considers a poorly run city government to a failing corporation were well received by the audience of mostly white, primarily older and primly dressed women. He was given a standing ovation.

In a city where only one of every 11 registered voters is a Republican, Fletcher has made appeals to Democrats, disgruntled from a close and at times bitter primary, to put him in office.

No such persons were on hand at yesterday's meeting of the League of Republican Women of the District of Columbia. Fletcher said afterwards, however, that his pitch was aimed at those persons who are "middle aged and upper-middle aged and senior citizens who are concerned about what they deem to be extremely permissiveness on the part of city authorities."

A large part of that constituency, city political observers believe, is made up of older, dieologically moderate and church-going blacks who primarily supported the two losers in the Democratic primary - Mayor Walter E. Washington and City Council Chairman Sterling Tucker.

Yesterday Fletcher was trying to shore up support among an influential part of the group - black baptist ministers. He met with two groups of churchmen, he said, including the John F. Kennexy League for Universal Justice and Goodwill, which backed Democrat John Ray in the primary (Ray later withdrew and supported Barry), and with the Baptist Ministers Conference of Washington, D.C. and Vicinity. That group supported Washington.

Many city political observers beleive that although Democratic party leaders offcically have endorsed Barry, and Tucker and Washington have urged Democrats to support his candidcacy, there is significant potential for Democratic support for Fletcher, especially among former Washington supporters.

In his statement on juvenile crime, Fletcher pledged to appoint a "youth commissioner" to oversee all city youth programs and to establish a "youth achievement commission" to encourage "constructive youth programs" in the city.

He could not say yesterday how these structures would differ from the current Office of Youth Advocacy, headed by James L. Jones, except to say they would be more effective. Fletcher also would not say if his program would require the replacement of Police Chief Burtell M. Jefferson.

Fletcher said that, if elected, he would crack down on traunts by using federal demostration and private foundation funds to increase city school staffs that enforce truancy laws.

He pledged greater community involvement in crime prevention efforts, more money for the police department's you division, and said he would urge the assignment of foot patrolmen to all parts of the city. Programs to "sensitize crime prevention efforts to the special needs of the elderly" also would be undertaken, he said.

Fletcher called for an improvement in the city's methods of collecting data on juvenile defendants and offenders and for more alternatives to traditional prosecution and incarceration. He also said he favored a "more comprehensive" - but undetailed - program to compensate victims of crimes.

Barry, whose campaign press secretary said is spending much of his time at private meetings with various city Democrats and on city council business, had no comment on Fletcher's statement.

The other two candidates in the election for mayor are Susan Pennington of the U.S. Labor Party and an independent, Glova E. Scott.