1. Coordinate all matters relating to crop pests and disease control;
2. Establish service laboratories to monitor the quality and levels of toxic residues in plants as well as their soils and produce;
3. Advise the Director of Agriculture on appropriate seeds and planting materials for export and import;
4. Administer Plant Breeders Rights in Kenya and be in the liaison office for the International Union for the Protection of New Varieties of Plants (UPOV), and be the custodian of the Plant Breeders rights register;
5. Undertake inspection, testing, certification, quarantine control, variety testing and description of seeds and planting materials;
6. Undertake grading and inspection of plants and plant produce at the ports of entry and exit;
7. Award scholarships for the study of Plant health services or any other related subject which the Board of Directors considers to be of benefit to the study of plant health;
8. Enforce standards for good husbandry and the control of pests and diseases in national irrigation schemes in conjunction with the National Irrigation Board;
9. Develop and implement standards on both imported and locally produced seeds;
10. Approve all importation and exportation licenses for plants and seed issued by the Ministry responsible for Commerce and Industry before such importation is implemented;
11. Implement the national policy on the introduction and use of genetically modified plant species, insects and micro-organism in Kenya;
12. Establish posts at convenient locations for quarantine, inspectorate and quality control of fertilizer and seed, and monitor agricultural inputs and their environmental effects;
13. Establish strong linkages an collaboration with various local and international governmental organizations so as to execute its tasks more professionally.

To adequately address its mandate as specified above, KEPHIS has formed the following service units: