[Results] All the data and information of total 343757 newborn screened from April of 2009 to March of 2011 include the information of newborn and their DBSS data, the laboratory test and its control data, the screening results and positive, the diagnosis and treatment information of babies with IMD can be managed freely. Parents can inquire about the baby' screening result on the appointed website by parents themselves. Discussion: NSIS is absolutely necessary. Appropriate NSIS make newborn screening to be high efficiency, high accuracy and high safety. NSIS should be improved and be perfected continually. Background: Approximately 1:1000 neonates are affected by congenital metabolic diseases in central Europe and 1:500 in Turkey. Undetected and untreated these diseases can lead to irreversible organ failures invalidity or death. Fully automated NMR spectroscopy of body fluids are used an analytical approach for diagnosis known, but also as yet unknown inborn errors of metabolism. Objectives: Primary objective of the study was to explore the range of variation (concentration and chemical shifts) of specific metabolites without clinically relevant findings. Secondary objective was the integration of the results from a healthy population of neonates into in NMRknowledge base to perform routine and completely automatic screening for congenital metabolic diseases using targeted and untargeted approaches out of one measurement per sample. Patients and methods: Urine samples of 512 neonates from 8 centers in Turkey were investigated by using fully automatic 500/600 MHz NMR spectroscopies. Results and Conclusion: In the urine of 20 neonates we found different pathological metabolites in high concentration. We present and discuss the NMR and clinical data of these children. The statistical analysis and quantification of metabolites allow developing a normal model in specific population also allowing a general assessment of the health state of newborn children. The UPLC-MS/MS method provided improved confirmation of analyte identity by the addition of a chromatographic separation step before mass spectrometric analysis. It decreased ion suppression from co-eluting substances, resulting in improved sensitivity that made it easier to distinguish between pathological and normal values. The method was in all cases able to distinguish between true and false positives. However, the positives were only considered really true positives when two diseasecausing mutations had been identified by mutation analysis. Background: Tandem mass spectrometry has allowed newborn screening programs to increase the number of disorders studied although more infants receive false-positive results. The number of these depends on the number of disorders screened and on the scenario(highly selected laboratories to real-world settings). Objective: To compare the expected number of false-positive results using available population-based studies with the real rate of these in our laboratory. Method:33.941 newborns were screened in 2010 from which we obtained the number of true-positives, false-positives, false-negatives and truenegatives, and calculated the sensitivity, specificity, PPV, NPV, prevalence and false-positive rate. We used the following equation (1):no. of false-positives= (1-(1-(1-prevalence) (1-specificity))k)*(no. of births), where k represents the number of tests performed with tandem mass spectrometry (24 primary targets) and prevalence refers to the average prevalence for an individual disorder screened (1 case per 111.997) (2) . Results: The estimated number of false-positive results was 34 for an expected specificity for an individual test of 99.995%(best-case scenario), 305 for a specificity of 99.95%(intermediate-case scenario)and 807 for a specificity of 99.9%(worst-case scenario). The real number of falsepositive results was 653 and the average specificity for each disease was 99.92%. Discussion: This estimation of specificities compares to real-world settings but all laboratories should document both their true-positive and falsepositive results.