Background  Anal abscesses are commonly associated with fistulas‐in‐ano and are usually polymicrobial in nature, with gram‐negative rods and anaerobes being the most prevalent isolates. Group Milleri Streptococci (GMS) comprise a heterogeneous group of cocci, which are capable of causing severe purulent infection with a high recurrence rate. Method  All anorectal infections caused by GMS, which were identified at our centre during a 4‐year period were retrospectively analysed. The 18 patients with GMS‐positive anorectal abscesses were matched with 36 GMS‐negative anorectal abscesses to identify outcome characteristics of this clinical entity. Results  During the study period, 358 patients underwent surgical treatment for anal infections; GMS were isolated in 46 individuals (13%) including 18 perianal abscesses, 11 pilonidal sinuses, eight fistulae in and nine miscellaneous infections. Seventy‐two per cent of perianal GMS infections were polymicrobial with E. coli and Bacteroides fragilis being the predominant second bacteria. Nine patients (20%) developed recurrent abscesses and fistulae‐in‐ano and underwent additional surgical interventions with resolution at follow‐up. Additional antibiotic treatment was administered in 10 patients with complex anal infections. Matched pair analysis revealed that GMS‐positive perianal abscesses were more commonly polymicrobial, and that the recurrence rate was higher (55.6% GMS‐positive and 22.2% GMS‐negative patients, P = 0.017). Conclusions  Our data confirm the propensity of GMS to form deep and recurrent abscesses with a higher recurrence rate than non‐GMS infections. First‐line treatment includes surgical drainage, and antibiotic treatment may be useful in selected patients.