Infectious diseases are common in internationally adopted children (IAC).With the objective to evaluate infectious diseases prevalence in a large cohort of IAC and to explore possible risk factors for tuberculosis (TB) and parasitic infections, clinical and laboratory data at first screening visit of all IAC (<18 years) consecutively referred to our Center in 2009 to 2015 were collected and analyzed.In total, 1612 children (median age: 5.40 years; interquartile range: 3.00-7.90) were enrolled, 123/1612 (7.60%) having medical conditions included in the special needs definition. The most frequent cutaneous infections were Molluscum contagiosum (42/1612; 2.60%) and Tinea capitis (37/1612; 2.30%). Viral hepatitis prevalence was <1% (hepatitis B virus [HBV]: 13 children, 0.80%; hepatitis C virus: 1 child, 0.10%; hepatitis A virus: 6 children, 0.40%). A parasitic infection was diagnosed in 372/1612 (23.10%) children. No risk factors for parasitosis were evidenced. Active TB was diagnosed in 4/1355 (0.3%) children, latent TB in 222/1355 (16.40%). Only 3.7% (51/1355) children had concordant positive tuberculin skin test (TST) and QuantiFERON-TB-Gold In-Tube (QFT-G-IT) results. Risk factors for TST+/QFT-G-IT- results were previous Bacille de Calmette-Guérin vaccination (adjusted odds ratio [aOR]: 2.18; 96% confidence interval [CI]: 1.26-3.79; P = 0.006), and age ≥5 years (aOR: 1.49; 95% CI: 1.06-2.11; P = 0.02). The proportion of children with nonprotective titers for vaccine-preventable diseases (VPD) ranged from 15.70% (208/1323) for tetanus to 35.10% (469/1337) for HBV.Infectious diseases were commonly observed in our cohort. The high rate of discordant TST/QFT-G results brings up questions regarding the optimal management of these children, and suggests that, at least in children older than 5 years, only QFT-G-IT results may be reliable. The low proportion of children protected for VPD, confirms importance of a timely screening.