Our study aimed to evaluate farmers' compliance in implementing recommendations of farmspecific cow comfort changes, and the effects of these changes on lying time, stall cleanliness and cow cleanliness using a randomized controlled trial carried out on 100 smallholder dairy farms in Kenya, with 62 and 11 farms remaining in the intervention and control groups, respectively. recommendations compared to farms that had the female principal farmer receive the recommendations (OR=0.01); 2) farms that had recommended changes related to roof, alley and sharps fixes relative to stall design fixes (OR=0.13). Post-intervention, stall, udder and upper hindleg cleanliness scores improved significantly (p<0.0001, p=0.021 and p=0.017, respectively) in the intervention farms but not in the control farms. There was no significant difference in lying times between intervention and control farms, with 0.6 and 0.2 hour/day increases being recorded in the intervention and control groups, from the 10.9 and 10.4 hours/day at baseline, respectively. Giving farm-specific cow comfort recommendations to smallholder dairy farmers in Kenya, and providing them with a participatory role in the formulation and implementation of improvement recommendations ensured good acceptance and a high degree of implementation, and led to a subsequent improvement in cow comfort and cleanliness.