Objective We performed single-photon emission computed tomography (SPECT) to investigate the influence of renal transplantation on cerebral blood flow (CBF). Patients and Methods Fifteen renal transplant recipients and twelve normal subjects underwent cerebral SPECT with N-isopropyl-p -[I-123] iodoamphetamine (I-123-IMP). All transplant recipients received prednisolone and cyclosporine (CyA). Regional CBF (rCBF) was measured by defining regions of interest in the cerebral cortex, deep white matter, striatum, thalamus, and cerebellum. In transplant recipients, correlations to the mean overall cortical CBF were assessed using the interval from transplantation to measurement of SPECT, as well as the serum creatinine concentration. Moreover, to investigate the influence of CyA on CBF, the correlation between mean overall cortical CBF and CyA trough concentrations was assessed. Results In all regions, CBF in renal transplant recipients was significantly lower than in normal subjects. No significant correlation was seen between serum creatinine, interval from transplantation, or CyA trough concentrations and mean overall cortical CBF. Conclusion Renal transplant recipients demonstrated a decrease in CBF, that can have an associated secondary pathology. Therefore, renal transplant recipients may benefit from post-operative MRI or CT.