Over the last three decades, the construction industry in the developing countries has experienced continuous increase in claims, liability exposures and disputes, along with increasing difficulty in reaching reasonable dispute settlements. The research aimed to investigate the impact of project characteristics on construction claims in Niger State. It was hypothesized that there is no statistically significant difference between size of a project or the project duration and claim amount in building projects in Niger State. The review of literature revealed five main causes of claims. The study used both quantitative and qualitative methods through administration of questionnaires and the analysis of secondary data such as the estimated project duration, and actual completion dates of 196 projects using descriptive and inferential statistics. The research revealed that unrealistic time targets, and poor communication, are two of the five major causes of claims. The study revealed that duration of project is the characteristic with the most influence in Niger State, and that both size and duration of a project have the tendency of increasing or decreasing simultaneously. It was recommended among others, that key players in construction projects should ensure that sufficient float is built into the schedule so that when delays do occur, they are absorbed into the contract and are less likely to become critical to the overall construction schedule.