There has been a considerable increase in annual cases of bacteraemia caused by beta-haemolytic streptococci serogroup G (GGS) and we therefore undertook a retrospective case review in the Danish County of Northern Jutland. During a 19-year period (1981-1999) 94 cases were identified in a regional bacteraemia register, and the annual incidence rose from 3.0 per 106 inhabitants in 1981-1987 to 7.4 in 1988-1993 and 17.2 in 1994-1999. Clinical charts were available for 92 cases. The male/female ratio was 52/40 and the median age 71 years, range 15-97 years. Twenty-seven patients had reduced functional capacity. Fifty-two cases were community-acquired. The most common site of infection was the skin followed by the lungs and the urogenital tract. Eleven patients had no apparent site of infection. Underlying disease was present in 81 patients, who shared 149 co-morbid conditions, and the overall one-month case fatality rate was 23% (95% confidence limits 15-33%). We conclude that GGS are of increasing importance as a cause of bacteraemic infections and first and foremost affect patients who are aged, debilitated, or suffer from severe or multiple underlying diseases.