There are delays in delivering construction projects, which have great affects in all countries' economies, due to many factors and reasons and these delays bring many negative consequences. Checking the source of these consequences or minimizing their effects is very important in terms of time and cost savings in the construction sector, especially for countries which have a continuous improvement such as Turkey. Determination of project factors that will cause delay, analysis of their impacts and taking protective measures will help to reduce losses. Hereby in this study, the project factors that may cause to delays are identified and some important association rules between these factors and delay are extracted by collecting the data from Turkish Public and private construction projects. Also, some recommendations were presented for reducing delays by using the extracted rules.