Background: To assess the performance of the Capintec- CRC-15R dose calibrator which is in use atLiaquat National Hospital (LNH) Karachi, Pakistan for patient dose administration. Method: This quantitative study was conducted at Nuclear Medicine department, Liaquat National Hospital,Karachi during the period from July-December 2015. The quality control tests of calibrator were performed using standard sources i.e. Co-57, Ba-133 & CS-137 and data was analyzed for performance assessment of calibrator. Results: Capintec CRC-15R calibrator was found in perfect working condition during daily physical inspections having consistent stable values with normal background readings. The precision test results were within the tolerance limits of ± 5% and accuracy of Co-57, Ba-133 & CS-137 were (-0.36%, -0.36% & -0.43%) respectively. The constancy tests for all the three (03) standard sources were within the specified limits of ± 10% and the activity-time graph was linear. The geometry test results were consistent upto 12 cm height (1.8%) and a sharp decrease of 11% was observed in activity at 20 cm height resulting in less activity measurements. The volume dependency results were consistent up to 3ml volume while a substantial deviation of 2.8 % was observed at 5ml which was within the tolerance limit of ±10%. Conclusion:The results of the quality control tests in our study for the dose calibrator- Capintec CRC-15R showed that the readings were within the specified limits and the calibrator was in good working condition which not only ensure right patient dose administration but also better staff protection.