Panipenem/betamipron (PAPM/BP) may be highly effective for life-threatening Streptococcus pneumoniae infection. However, the efficacy of PAPM/BP for S. pneumoniae infections has not been compared with that of other antimicrobial agents. We retrospectively compared PAPM/BP with other carbapenems for treatment of life-threatening infections in newly hospitalized adults with pneumococcal bacteremia. Clinical information for cases of pneumococcal bacteremia was collected from three teaching hospitals in Japan from January 2003 to December 2010. In total, 17 patients who received PAPM/BP therapy and 34 treated with other carbapenems (27 with meropenem, 4 with imipenem/cilastatin, and 3 with biapenem) were identified. The mean age (71 vs. 70 years old), sex distribution (women, 29 vs. 21 %), Charlson comorbidity index (CCI) (1.5 vs. 1.6), and rates of septic shock (29 vs. 38 %), and meningitis (5.9 vs. 8.8 %) did not differ significantly between the two groups. The inpatient mortality rates were lower in the PAPM/BP group (12 vs. 44 %, p = 0.03). Multiple logistic regression analysis adjusted for age, sex, CCI, and severe sepsis/septic shock showed that use of other carbapenems was associated with higher in-hospital mortality, with an odds ratio of 6.922 (95 % CI, 1.171-40.92) compared to PAPM/BP therapy. Initial PAPM/BP therapy might have a therapeutic advantage over other carbapenems in treatment of severe Streptococcus pneumoniae infections.