Introduction: Quality indicators in a clinical laboratory are considered as useful tools for continual improvement of the laboratory services. Aim: The aim of this study was to assess timely performance of the Gujarat Cancer & Research Institute (GCRI) service laboratories in three phases of testing – pre–analytical, analytical and post–analytical, in an effort to improve their performance. Methodology: The study included an assessment of different quality indicators from central laboratory – Hematology, at GCRI which provide service for the patient care. Results: Data obtained from a total of 490349 samples collected over a period of three years was used in the study. The overall error rate was found to be 2.72%. The commonly observed indicators were clotted sample (3.62%) followed by low quantity (0.99%) of samples during the pre–analytical phase. In the analytical phase, IQC failure (0.27%) was the most common in the three years study period, TAT outlier was 1.2%, during the post– analytical phase. Conclusions: Quality indicators are important tools in improving the quality system in a clinical laboratory and patient care.