Objective: To compare in vitro knot holding strength of the laparoscopic Miller's knot (LMK), open Miller's knot (MK), open surgeon's throw (Sx), and laparoscopic surgeon's throw (LSx) in a vascular pedicle model when used as the first throw for vascular ligation. Study design: Experimental study. Sample population: Ten constructs each of the Miller's knot and surgeon's throw performed openly and laparoscopically with 2-0 polyglyconate suture. Methods: Knot holding strengths of the LMK, MK, LSx, and Sx knots were evaluated on balloon dilation catheters used as vascular pedicle models. Laparoscopic knots were tied in a laparoscopic box trainer. Knot constructs were pressure tested to failure. Results were compared by Kruskal-Wallis and Steel-Dwass comparisons. Results: Both MK and LMK had mean leakage pressures above 300 mm Hg. The MK leaked at higher pressure than all other knots, including the LMK (P < .001). The LMK leaked at greater pressures compared with the Sx and the LSx (P < .001). No difference was detected between leaking pressures of the Sx and the LSx (P = .226), with both leaking at pressures below 40 mm Hg. Conclusion: The LMK created a more secure first throw compared with the Sx and leaked at supraphysiologic pressures. Clinical significance: The LMK has excellent knot holding strength on a vascular pedicle model and may be further evaluated for clinical application. 1 | INTRODUCTION Minimally invasive surgery (MIS) continues to increase in popularity and demand in veterinary medicine. 1,2 Vascular ligation with suture is a basic skill in traditional surgery that can be challenging and time consuming to perform laparoscopically.