We conducted a retrospective analysis of acute bacterial prostatitis (ABP) to evaluate the factors of progressing to chronic infection and chronic pelvic pain syndrome IIIa (CPPS IIIa) from ABP. The clinical records of 480 cases compatible with a confirmed diagnosis of ABP from five urological centers between 2001 and 2010 were reviewed. We defined chronic infection (CI) as a progression to chronic bacterial prostatitis (II), epididymo-orchitis, and showing persistent pyuria and bacteriuria after treatment of ABP in admission periods when followed up at 3 months or more. Results were analyzed according to two categories: category I, developed to CI (group A, n = 49) versus recovered without CI or CPPS IIIa (group C, n = 385); and category II, developed to CPPS IIIa (group B, n = 46) versus recovered without CI or CPPS IIIa (group C, n = 385). Of the 480 ABP patients, 10.2% (49/480) progressed to CI and 9.6% (46/480) progressed to CPPS IIIa. The frequency of CI was 11.3% (49/434) and that of CPPS IIIa was 10.7% (46/431). The factors that affected progression to CI were diabetes, prior manipulation, not doing cystostomy, and urethral catheterization (P < 0.05). The factors that affected progression to CPPS IIIa were the same as CI, but prostate volume was included in the CPPS IIIa group (P < 0.05). The identification and characterization of these factors may accelerate the development of preventive, diagnostic, and therapeutic strategies for the treatment of CI and CPPS IIIa from ABP.