Blood and cerebrospinal fluid (CSF) acidosis is the most troubling complication in subarachnoid hemorrhage (SAH) if carotid body (CB) networks are disrupted. However, histopathological examination of the choroid plexus (CP) in acidic CSF has not been evaluated so far. In this study, we aimed to investigate the CP in acidic CSF following SAH. Twenty-eight rabbits were used. Five rabbits were used to analyze CB network (control group;n= 5); seven rabbits were injected 1 mL of saline (Sham group;n= 7); and the rest 16 rabbits were given 1 mL of autologous arterial blood inject into the cisterna magna to create SAH (SAH group;n= 16). Blood and CSF pH values were recorded before/during/after the experimental procedures. Nuclear darkening, cellular shrinkage and pyknosis suggested the presence of apoptosis of epithelial cells of CP. The densities of normal and degenerated epithelial cells of CPs were estimated using stereological methods. The relationship between the pH values and degenerated epithelial cell densities of CPs were statistically compared by Mann-WhitneyU-test. The pH values of blood were estimated as 7.359 +/- 0.039 in the control group, 7.318 +/- 0.062 in the Sham group, 7.23 +/- 0.013 in the SAH group. CSF pH values were 7.313 +/- 0.028 in the control group, 7.296 +/- 0.045 in the Sham group, and 7.224 +/- 0.012 in the SAH group. Degenerated epithelial cell density of CP was 25 +/- 7 in the control group, 226 +/- 64 in the Sham group, and 2115 +/- 635 in the SAH group. There was a considerable link between CSF pH values and degenerated epithelial cells of CP (P < 0.0001). This study shows that CB insult causes acidosis of CSF as well as cellular degeneration of CP during SAH. This is the first description of this in the literature.