The topic of this project is the development of a user identification system using an optical fingerprint sensor. The system is intended for recording the presence or records of the arrival of an individual user. The hardware of the system is made using an optical fingerprint sensor used for taking a fingerprint, Arduino Uno board in which the Arduino program is transferred using Arduino IDE integrated development environment, 16×2 LCD module for printing individual system functionalities, 10kΩ potentiometer for contrast control on 16×2 LCD screen and an breadboard for connecting all parts of the system. Within the Arduino code that we transfer, we have user registration functions for entering the user's fingerprint in the database using the ID number and user login or if the user's finger matches any of the stored fingerprints, the user successfully logged in and displays the login user ID number. There are other functions like deleting a single fingerprint from the sensor base and deleting the entire sensor base. To simplify the use of the system, we created a user interface using the C# programming language that we linked to the Arduino code. The desktop application, that is user interface, is connected to the database using an SQL server in which we store user login and registration data. In addition to storing the user ID number or fingerprint in the sensor, we save the ID number, name, surname, date and time of registration or login of the user in the database within the SQL server. Records are securely stored and can be retrieved reliably whenever required by the application user. When the user logs in successfully, the 16×2 LCD screen displays the successful login of the user with the specified identification number. In order to successfully register presence of the users with a finger, they must first register with an identification number, name, surname and fingerprint. After the user has completed the registration process, they can register or check attendance.