An experiment was conducted to examine effects of supplemental lysophospholipids (LPL) in dairy cows. Eight cannulated lactating Holstein cows were used in a repeated 4 × 4 Latin square design. Dietary treatments were CON, a dairy ration (55% forage and 45% concentrate on a DM basis); MON, the control diet supplemented with monensin (16 mg/kg in dietary DM; Elanco Animal Health; positive control); L-LPL, the control diet supplemented with low LPL (0.05% in dietary DM; Lipidol Ultra, Easy Bio Inc.); H-LPL, the control diet supplemented with high LPL (0.075%). Experimental periods were 21 d with 14-d diet adaptation and 7-d sample collection. Daily intake and milk yield were measured and milk samples were collected weekly. Spot urine and fecal samples (8 samples per cow) were collected for 3 d to determine nutrient digestibility and dietary N utilization. All data were analyzed using the MIXED procedure of SAS where the model included group and cow within group as random and treatments, time, and their interaction as fixed. Preplanned contrasts were made to determine linear effect of LPL and effect of LPL vs. MON. Supplementation of LPL to the diet did not alter DMI but linearly increased (P < 0.01) milk yield, resulting in linear increases (P < 0.01) in feed efficiency (milk yield ÷ DMI) and milk protein and fat yields. However, total-tract digestibility of DM and OM tended to be lower (linear P ≤ 0.07) for LPL compared with CON. In addition, linear decreases (P ≤ 0.02) in urinary N excretion and urinary N excretion as % of total intake N were observed. Comparing to MON, supplementation of LPL increased (P ≤ 0.10) milk fat content and yield and estimated microbial N production in spite of decreases (P ≤ 0.04) in apparent DM and OM digestibility. In conclusion, LPL is a potential feed additive that can increase milk yield and components and dietary N utilization. However, the mechanisms for the positive effects clearly differ between LPL and monensin according to milk fat and microbial N production. Further studies are needed to examine the roles of LPL in dairy cows.