Purpose: The use of antibiotic prophylaxis in dental implant surgery is a routine dental practice to prevent implant failure. Current systematic reviews have yet to confirm the effectiveness of antibiotic treatment at reducing postoperative infection rates in implant procedures. The aim of this study was to quantify amoxicillin plasma levels at the peripheral venous blood and at the surgical implant site in patients undergoing dental treatment. Materials and Methods: A prospective study was conducted. Patients undergoing dental implant surgery were selected, and preoperative doses of 1 g of amoxicillin, in the form of an oral tablet, were administered 1 hour prior to implant surgery. The blood samples (1.5 mL) were collected from both the venous and implant sites. Data on the antibiotics were measured using high-pressure liquid chromatography. The quantification method was validated for linearity, selectivity, and detection limits. Statistical analysis of plasma antibiotic was performed, comparing both samples and the age, height, weight, and body mass index (BMI) (Wilcoxon test, P .05; STATA v.10.0). Results: Thirty-two patients (mean age: 56.28 ± 12.2 years; range: 31 to 79 years; 20 men) were selected. Both blood samples were taken at a mean 1.16 ± 0.37 hours after antibiotic intake. The mean amoxicillin concentration at the implant site reached 5 ± 2.63 μg/mL (range: 2.04 to 11.18 μg/mL), while the venous blood level was 4.21 ± 2.12 μg/mL (range: 1.6 to 9.98 μg/mL) (P = .33). No correlations were observed between age, height, weight, and BMI with antibiotic plasma levels. Conclusion: These findings demonstrate that plasma concentrations of a prophylactic dose of amoxicillin are higher than the minimum inhibitory concentration needed to prevent the common dental bacteria involved in peri-implantitis and periodontal diseases. Keywords: antibiotic prophylaxis, chromatography, dental implants, oral surgery, plasma concentration