Synopsis Exotic softwoodtree species playamajorrole in Rwandan plantationforestry. Theyareusedto produce sawn timber used for various purposes. Pinus patula is the major commercial species. Growth and yield of this species were compared in terms of seed source variation based on two trials, one established in MuhangaNdiza, Mushubati District, Gitarama Province at 16 years and anotherin Cyeru District, Ruhengeri Province at 15 years. Yield comparison was also made between P. patula and other new species being tested namely P. caribaea, P. kesiya, P. maximinoi and P. tecunumanii. Although results are variable, it seems that genetic gains are possible in P. patula through the use of appropriate geographic sources. Landraces from otherAfrican countriesmayplay a majorrole inestablishing a simple breeding strategy based on more seed introductions. Very significant improvements in volume production can be achieved through the use of other promising species such as P. maximinoi and P. tecunumanii. Furthertesting andimprovementmayconfirm the potential ofthe two species since the current conclusions were drawn from results from small trials. Furtherimprovementsmay possibly be achieved by introducing othertropical pine species such as P. oocarpa and also through crossing ofrelated species. Unlike the other pine species, P. kesiya provedto be poorly adapted to local conditions and should not be considered inRwanda as a plantationtree species. Itis recommended that improved germplasmfrom external sources be included to accelerate the tree improvement programme for the most promising species in Rwanda.