Bus dwell time, which is the time needed for buses to board and alight passengers at busrnstops or stations and door opening and closing time, is one of the components bus travelrntime. Longer dwell times and variability of dwell times leads to an increase in total travelrntime thus passenger delay and passengersâ€™ discomfort is eminent. The variability ofrndwell time makes the schedule of Addis Ababa city bus enterprise agenciesrnunpredictable. The emphasis of this research is so to identify and quantify therndeterminant factors which play a role to the variability and increase of dwell time ofrnAddis Ababa City buses and to develop multiple linear regression models to predictrndwell time based on manually collected data of nine routes in Addis Ababa. rnPassengers boarding and alighting, number of standing passengers, fare collection media,rntime periods of the day, floor levels of buses, number of lanes of the roads the busrntravelling on, and bus types are the factors considered in the research. 868 dwell timerndata are collected manually for the research and terminus stops are not considered as theyrnlead to wrong bus dwell time estimation. rnThree types of analysis are involved: statistical and regression analysis along with modelrndevelopment. The results of the analysis are presented and interpreted in tabular, chartrnand in calculation forms. Dwell time takes up to 14% on average of the total travel timernof the studied routes and the minimum recorded dwell time is 5 seconds and the largestrndwell time is 175 seconds. The average dwell time is 25.64 second and the overall dwellrntime model has a significant value of F less than 0.05. Finally the 12 closed typernquestions were presented to 60 bus users and the response of the questionnaire arernincluded in the research. In addition to this the capacity of bus stops and performance ofrntwo bus stops are done.