Research studies presented inconsistent results on the effects and action of choline in dairy cow diets. A meta-analysis was conducted to quantify the effects of dietary rumen-protected choline on production characteristics of dairy cows. Dry matter intake (kg/d), milk yield (kg/d), milk fat (% and kg/d) and milk protein (% and kg/d) were evaluated as dependent variables in models. The number of treatment means varied from 20 obtained in 7 studies for milk fat and protein contents, to 34 from 11 studies (12 experiments) for milk yield. With accounting for experiment as a random effect, DMI, milk yield, milk protein content and milk protein yield could adequately be related to levels of dietary rumen-protected choline chloride by a logistic model. Marginal responses in milk yield decreased from 131.5 to 0.037 g of milk per gram of dietary rumen-protected choline chloride when supplementation increased from 6 to 50 g per day.