Many filamentous fungi from the genus Trichoderma are well known for their anti-microbial properties. Certain genes from Trichoderma spp. have been identified and transferred to plants for improving biotic and abiotic stress tolerance, as well for applications in bioremediation. Several Trichoderma genomes have been sequenced and many are in the pipeline, facilitating high throughput gene analysis and increasing the availability of candidate transgenes. This, coupled with improved plant transformation systems, is expected to usher in a new era in plant biotechnology where several genes from these antagonistic fungi can be transferred into plants to achieve enhanced stress tolerance, bioremediation activity, herbicide tolerance, and reduction of phytotoxins. In this review, we illustrate the major achievements made by transforming plants with Trichoderma genes as well as their possible mode of action. Moreover, examples of efficient application of genetically modified plants as biofactories to produce active Trichoderma enzymes are indicated.