Just under a quarter of Boston’s population is black, but black residents are 63 percent of those stopped-and-frisked by the Boston Police Department, according to a new report published today by the Massachusetts chapter of the American Civil Liberties Union.

The study analyzed more than 200,000 encounters not resulting in arrest between the Boston police officers and civilians (classified by the department as “field interrogation, observation, frisk and/or search) between 2007 and 2010. In 75 percent of those cases, no reason or probable cause for the search was recorded by the police other than “investigate person.” Of the 200,000 encounters, only 2.5 percent resulted in the seizure of contraband.

Researchers found that, even after controlling for crime, stop-and-frisk encounters were more likely to occur in the city’s traditionally black neighborhoods — with more than 100,000 of the stops occurring in minority-rich neighborhoods of Roxbury, Dorchester and Mattapan — than in traditionally white parts of the city.

“The bottom line,” the report’s authors declare, “is that race was a significant factor driving the BPD’s stop-and-frisk practices.”

“The ACLU’s report underscores our need to be vigilant in every city across this country, including Boston, to stop bad, racially motivated policing that doesn’t deter crime,” said Michael Curry, the president of the Boston NAACP. “Flawed stop and frisk and policing policies and practices leave too much discretion to police officers, and ultimately infringe upon the rights of black and brown people. While we share a desire to stop and prevent crime by the few, it shouldn’t come at the expense of the majority of law abiding citizens.”

Boston police did not immediately respond to requests for comment. Former Boston police commissioner Ed Davis, who ran the department for all of the years included in the new study, could also not immediately be reached for comment.

The report comes as cities across the country continue to grapple with the use of stop-and-frisk and as the nation has been thrust into a renewed conversation about racial profiling and how police interact with minority communities. A series of high-profile police shootings this summer, including the Aug. 9 slaying in Ferguson, Mo., of unarmed black 18-year-old Michael Brown by a white officer, has drawn new attention to issues of profiling.

Civil rights groups have for years decried “stop and frisk” policies, most notably in New York, where analysis of random street stops found not only that the stops disproportionately targeted minorities but also yielded relatively few arrests.

Last month, the NAACP called on Congress to pass legislation to outlaw racial profiling in policing and issued a comprehensive report on racial profiling — specifically citing the use of stop-and-frisk practices in many large American cities as the next frontier in battling prejudicial policing.

“An unfortunate and persistent reality of our history is the fact that people of color continue to be profiled and viewed as criminally suspect based on their race and ethnicity,”  Barbara Bolling-Williams, chairwoman of the NAACP’s Criminal Justice Committee, said in that report.