Background: Calreticulin (CALR) is a 46 kDa protein in the endoplasmic reticulum and is one of the major proteins in ca2+ binding; it has a key role in oxidative stress, transcription factor activation, and as a chaperone in newly synthesized protein and glycoprotein folding. The high expression of CALR is pivotal for cardiac development in the embryonic period. It has been showed that mutation in exon 9 of CALR causes loss of C-terminal function and contributes to cardiovascular disease (CVD) development. Objective: It could conceivably be hypothesized that in addition to the general risk factors, the specific gene defects which are less considered can contribute to CVD development. In this regard in this study the possible existence of CALR mutations in CVD development is determine in patients younger than 40. Method: Thirty patients younger than 40 were recruited for this study, 86.7% (26) were male, and just 13.3% (4) were female. The amplification refractory mutation system-PCR was used to identified mutation in exon 9. The CVD risk factors, including blood pressure, type 2 diabetes, dyslipidemia, history of smoking, alcohol drinking, and familial CVD development were evaluated. Result: In none of the patients, CALR mutations were detected. Since CALR defect causes accumulation of glycogen in the heart's cells and contributes to CVD development, our results confirm this, so that 76.7% of patients did not have diabetes. Conclusion: The findings of the current study show there is no significant differences between exon 9 CALR mutation and CVD development.