We introduce hyperpolarized [1,5-13C2]Z-OMPD as a novel in vivo pH sensor. Upon synthesis from ethyl pyruvate, the molecule appears to be non-toxic and shows good hyperpolarization properties, as indicated by high polarization levels and long T1 relaxation times for both 13C-labels. 13C-chemical shifts show good pH sensitivity in the physiological range, which enables pH imaging in vitro of human blood phantoms of different pH. In vivo pH imaging upon injection in rats reveals previously reported pH compartments in kidneys. It is further demonstrated, that the OMPD1 peak can be used as internal reference, further facilitating the process.