The increase in complexity in software development is followed by higher pressure on several factors such as time-to-market. Software development projects are, however, found to often run over time due to many uncertainties throughout the project. Agile methodologies have become popular in managing software development projects due to their flexible, short-term, and iterative approach to working and planning. There is however a dilemma between being agile without fixed plans, and simultaneously having pressure from management and customers to set and meet a deadline, based on long-term plans. The Agile way of working includes self-organized teams that are involved in project management tasks such as planning and estimating. Agile teams create their own variances of different Agile frameworks as well as their own team characteristics, planning methods, and working ways. Important characteristics of Agile teams are, for instance, cross-functionality and adaptation. Agile planning includes activities such as the breakdown of work, effort estimation, prioritization, task assignment, and planning of iterations. These activities are commonly used in software development teams to manage their work and increase the ability to deliver on time.  This study aims to investigate how software development teams plan their work in practice and what Agile planning activities and Agile team characteristics are regarded, by the development teams, to be important for on-time delivery. Furthermore, it is interesting to investigate how the identified activities and characteristics are reflected in the teams’ actual planning. A case study is conducted on two software development teams at Ericsson’s organization Cloud RAN to investigate this matter.  The studied software development teams are found to use variations of Agile methodologies. The thesis identifies a number of Agile planning activities and team characteristics to be regarded, by the teams, as important for on-time delivery. Many of these activities and characteristics are also reflected in how the teams actually plan. However, there are some contrasting opinions regarding the activities and team characteristics. It can therefore not be stated that all the identified Agile activities and team characteristics are reflected in the actual team-level planning. The thesis also includes other findings impacting teams to deliver on time as well as factors affecting team-level planning.