The report from the Brazilian Forum on Public Security found that 1,890 people in 23 Brazilian states were killed in such circumstances in 2012, including 1,322 just in the states of Sao Paulo, Rio de Janeiro and Bahia.
This compares with the deaths of 89 civilian and military police in the line of duty nationwide during the same period, or one police officer for every 21 civilians killed in police clashes, it noted.
"In the United States, with a population 60 per cent bigger than that of Brazil, 410 people were killed in a confrontation with police in 2012," O Globo reported.
It blamed the high fatalities on a variety of factors, including police forces beset by "a culture of violence" and nonexistent controls.
Sao Paulo, Brazil's most populous state, recorded the highest number of deaths in clashes with police -- 563 last year.
Yet the mere replacement of Sao Paulo state security chief led to a 64 per cent drop in the number of such fatalities from January to May this year compared with the same period last year, the survey said.