Port Said University uses decorative granite in its building supplied by the Egyptian industry. The qualitative and quantitative interpretation was carried out on the geological laboratory covered by Egyptian granitic countertops. Qualitatively, uranium anomalies are randomly oriented and spread all over the laboratory showing trapped radon gas which increases the indoor radon emissions. Quantitatively the measured activity concentrations of 232Th, 226Ra, and 40K recorded in the geological laboratory are higher than Faculty's yard which reaches 5, 3.5 and 4.5 times respectively. Radium equivalent, external hazard index and internal hazard index of Egyptian granitic countertops recorded 244.088, 0.659 and 0.965Bq/kg, respectively. The indoor absorbed dose rate calculated from the measured activities is 220 nGy/h. Also the average annual effective dose rate is 0.438 mSv/y which is very close to the average values of annual effective dose equivalent (indoor) of 450μSv/y. Consequently, the higher internal hazard index, absorbed dose rate, average annual effective dose rate of granitic countertops reflect the indoor exposure to radon and its daughter products which is mainly harmful on the occupancy and the increase of health risks to workers (professors, students and labors). Finally, the activity concentration index of geological laboratory is 1.832mSv/y which extremely exceeds 1 mSv/y. The Excess Lifetime Cancer Risk (ELCR) factor assessed during the present study on the basis of indoor annual dose was found to be 1.61x10-3, which is more than five times the world's average of 0.29x10-3. As a result, the activity concentration index and ELCR are also an alert about constructing decorative cover (granitic countertops) in laboratories as continuous attending place for humans such as in the Universities. As a confirmation of domination of radon in granitic countertops in geological laboratory as the most contributor and first responsible of the indoor exposure inside the geological laboratories, therefore the present study is expected to be helpful in creating baseline data and in setting standards on radiation exposure for natural series nuclides in locally produced granitic countertops.