How safe is getting a vasectomy? Wondering about the safety of a Vasectomy? Let's dive into the statistics and evidence to understand the low risk and high success rate of this popular procedure. 1. National Insitute of Health of the US Gov: “Vasectomy is the most effective form of sterilization for men.” 2. Probability of Success = 99.99% 3. Probability of Failure = 1 out of 10,000 (and this is at the 3 Month mark and LATER) Probability Possible Long-Term Complications from a Vasectomy: 1. Sper