There was lack of adequate knowledge and information on the status and risks posed to Plant genetic resources in Kabale highlands especially with cultivated crop species. Therefore, this study was to document genetic diversity and study genetic erosion in cultivated crop species so as to develop effective strategies for conservation and sustainable utilization of these resources. Data were collected from a random sample of 120 farmers in 6 parishes using a structured pretested questionnaire and analyzed by SPSS for descriptive statistics. Germplasm was collected using IPGRI germplasm collection form. The major cultivated crop species were banana/plantain (Musa spp), sorghum (Sorghum bicolor. L), peas (Pisum sativum. L), beans (Phaseolus vulgaris L.), potato (Solanum tuberosum. L) and sweet potatoes (Ipomea batatas. L) and 25, 10, 6, 28, 13, and 17 cultivars/varieties of these crop species, respectively were identified on the farmers’ fields. Minor crops grown include Yams (Dioscorea spp), tobacco (Nicotinum tabacum), groundnuts (Arachis hypogea), coffee(Coffea spp), cassava (Manihot esculenta), sugar cane (Saccharum officinarum L), maize (Zea mays L), finger millet (Eleusine corocana). L), wheat (Triticum aestivum), fruits and Vegetables. Much genetic erosion had occurred to sweet potatoes, potatoes, beans and peas as many varieties were lost completely and others were on the verge of extinction. Other threatened crop species were finger millet (Eleusine corocana. L), wheat(Triticum aestivum), and pumpkins (Cucurbita spp). The most underlying cause of genetic erosion as mentioned by many farmers (93.7%) was introduction of new varieties. There were two main sources of farmers’ seeds (formal and informal). The formal one was mainly used for new/modern varieties as many farmers (50.8%) relied on cash purchase from market and informal one for traditional varieties as many farmers (81.5%) relied of their own stock. There was a lot of seed exchange of modern varieties between the farmers. This has resulted in fast and wide spread of modern varieties and has led to the abandonment of the traditional ones. Sixty seed specimens representing four crop species (beans, sorghum, peas and maize) were collected and conserved at MUARIK, Gene Bank. The loss of traditional varieties results in reduction of the genetic base of the remaining varieties that may have a consequence upon changing environmental and ecological conditions. Therefore, the loss of landraces is a threat to national food security and future genetic improvement programs. There is therefore, an urgent need to collect, document, characterize, conserve and utilize the traditional crops and formulate policies that will protect them from further genetic erosion.