Objective: ¹⁷⁷Lu-DKFZ-PSMA-617, a urea based compound binds to the extracellular domain of PSMA thus providing an effective target for the treatment of castration resistant prostate cancer (CRPC). Prior to its therapeutic use, the radiation dosimetry of this radiopharmaceutical is necessary to be studied to determine the safe activity that can be administered in patients in order to prevent haematological, renal and liver toxicity. The present study was thereby directed to assess the pharmacokinetics and dosimetry of ¹⁷⁷Lu-DKFZ-PSMA-617 in CRPC patients. Methods & Materials: After obtaining ethical clearance from the institute ethics review board, we enrolled CRPC patients who were positive on Glu-NH-CO-NH-Lys-(Ahx)-[⁶⁸Ga(HBED-CC)] PET/CT scan. The mean administered activity in the overall population was 2.52±1.3GBq. For dosimetry purpose, each patient underwent 9 planar whole body scans along with blood and urine sample collection at 0.5, 3.5, 24, 48, 72, 96, 120, 144 and 168 hours, respectively. SPECT/CT was done to derive the volume of salivary glands (parotid and submandibular glands) and tumour. Dosimetric evaluation was done using the OLINDA/EXM 1.0 software. Results: 31 CRPC patients with a mean age of 65.51±9.86 years (range: 38 - 81) were recruited. Normal physiological uptake was seen in all the patients in lacrimal glands, parotid glands, submandibular glands, liver, spleen, kidneys, intestines and urinary bladder. Organs having highest absorbed doses were the salivary glands (parotid and submandibular) followed by the kidneys, receiving 1.209 ± 0.256 mGy/MBq and 1.02 ±0.31 mGy/MBq, respectively.  The mean absorbed doses to the liver, urinary bladder and red marrow were 0.37 ± 0.100 mGy/MBq, 0.23 ± 0.08 mGy/MBq and 0.048 ± 0.05 mGy/MBq, respectively. The mean whole body dose was 0.016±0.003 mGy/MBq. Conclusion: ¹⁷⁷Lu-DKFZ-PSMA-617 therapy is a safe option in the treatment of CRPC patients.