Contractors’ budgeted cost overrun is treated as a regular feature in construction projects. It was evident that the major impact for the contractors’ budgeted cost overrun has happened with the material cost and labour cost. Hence, the paper aims to find common causes for the material and labour cost overruns as well as strategies to reduce the impact on the contractors’ budgeted cost overrun. A comprehensive literature review along with the expert interviews under the qualitative research approach was adopted during the data collection. Subsequently, frequency analysis was adopted to analyse data collected through interviews. The study identified 10 and 12 common causes for material and labour cost overruns respectively which can influence the contractors’ budgeted cost overrun. Further, 7 common strategies were identified to minimise the material and labour cost overruns under each category. As the next step, future research should aim to provide statistical methods to inspect and analyse the impact level of significant cost variables on the contractors’ budget.