Introduction: Over the last 20 years Interventional cardiology has expanded significantly,both in the field of diagnosis and therapy.These intervention procedures are performed under fluoroscopic guidance and become increasingly common because of their obvious benefits to patients.Patient dose during cardiologic procedures is considered to be high due to lengthy procedure and the prolonged exposure time to the patient.Since,no studies were made at the regional level(north-east India)to estimate the significance of the radiation doses,it is necessary to obtain the local diagnostic reference level for optimization of radiation protection.Objective: The primary objective of the study was to evaluate the level of radiation dose received by the patients in order to estimate local diagnostic reference levels during cardiac catheterization procedures individually in terms of DAP(dose area product),ESD(entrance surface dose)and E(effective dose).Material and Methods: A total of 123 patients were included in these studies,who were admitted to Cardiology department,and the following data were collected retrospectively in a designed format during both diagnostic(Coronary angiography)and therapeutic procedure(Percutaneous Transluminal Coronary Angioplasty):Patient demographic data like sex,age,weight and height.Digital readout of cumulative DAP(Dose area product)and ESAK(Entrance Surface Air Kerma).Exposure factors: mAS,kVp,exposure time(both fluro and total including cine)For analysis of data,continuous variables were checked for normal distribution using K-S test(Kolmorogov-Smirnov).Normally distributed data and non-parametric data were compared using the Students t-test and Mann-Whitney U test respectively.Correlations between continuous variables were obtained by the Pearson correlation coefficient.P<0.05 was considered as statistically significant.Results: The estimated patient dose rate as a whole in the Cath-Lab was found to be 96.45mGy/min which is considered lower than the recommended DRL(dose reference level)for the continuous high mode fluoroscopy used in interventional radiology(100mGy/min)given by IAEA.The mean estimated value of DAP were 32.43(range 11.85-91.74),57.16(range 28.95-151.2)and 120.6(13.94-319.1)Gycm2 for CA-TFA(coronary angiography with trans-femoral approach),CA-TRA(coronary angiography with trans-radial approach)and PTCA(percutaneous Transluminal coronary angioplasty)respectively.The estimated value of ESD for all three procedures were 0.44Gy(range 0.162-1.30),0.83Gy(range 0.47-2.14)and 2.29 Gy(range 0.93-4.28).The effective dose were also calculated and found respectively as 7.13mSv(range2.61-20.18),12.58mSv(range 6.37-33.27)and 26.53mSv(range 3.07-70.21).We observed strong correlation between total duration of procedure(both fluoroscopy and cine time)with both effective dose(R=0.95,p<0.00001)and entrance surface dose(R=0.969,p<0.00001)and a weak although statistically significant correlation between BMI(body mass index)with both effective dose(R=0.525,p<0.00001)and entrance surface dose(R=0.481,p<0.00001)were observed..A ignificant increase of doses in TRA procedure in regard to TFA procedure was also noticed in our study.Conclusions: Patient and staff dose reduction is of a prime importance and practitioners should optimize the radiation dose by applying proper technique without compromising the diagnostic and therapeutic findings.It is anticipated that this study is going to assist the institutions having Cath-Lab facilities of this region in encouraging the standardisation of procedure,which may help increase awareness and aims to serve as guidance for Cardiologist.