Infectious meningitis is a medical emergency. Within the spectrum of infectious agents, the most important is Streptococcus pneumoniae, the most frequent etiological agent of bacterial meningitis. The initiation of empirical antimicrobial treatment bears great importance and considers third-generation cephalosporins as the first alternative. However, cases of ceftriaxone resistance have been reported in several regions of the world. This has become an emerging problem in need of reconsideration of the current empirical antibiotic treatment schemes. We present the case of a 56-year old man with acute infectious meningitis caused by ceftriaxone-resistant Streptococcus pneumoniae, who responded favorably to combined empirical treatment with ceftriaxone and vancomycin and to whom, during his hospital stay, the presence of hypothyroidism and mega cisterna magna was diagnosed.