The main objective of this research was to identify the predominant or natural periods of targeted unreinforced masonry (URM) buildings by performing ambient vibration tests to compare the obtained structural predominant period with the structural period calculated by the formula given in the Bangladesh National Building Codes. The study also found a relationship between the structural period and different structural parameters of URM buildings. This paper presents an evaluation of ambient vibrations and identifies the predominant frequencies of 17 URM buildings. The buildings range from a single story to five stories and have regular and irregular plans and elevations. The buildings are located in Dhaka, the capital city of Bangladesh. These masonry buildings were constructed from 1960 to 1990 without any seismic guidelines. An attempt was made to correlate structural periods with heights and with total length of structure walls using MS Excel plots and a Statistical Package for the Social Sciences model. In order to find a realistic solution, multivariate regression analysis was selected for model development where the structural period was the dependable variable. The correlations through regressions were successfully identified.