In this study, Air Quality Index (AQI) in Besiktas was intended to be predicted by Artificial Neural Networks (ANN) and k Nearest Neighbors (kNN) algorithms. For this purpose, eight parameters have been selected which may affect the AQI. These parameters are PM10, SO2, CO, O3, temperature, humidity, pressure and wind speed, respectively. 124 data for 2015, 2016, 2017 and 2018 January, which includes eight parameters, were determined as training data. The first 14-day data of January 2019 were determined as test data. Similarly, the first 14-day data of January, March and December of 2018 were used as test data. In addition, The first 14-day data for January 2019 were normalized and set as test data. The success of ANN and kNN were measured by comparing.