This study describes the results of a survey of the resistance training practices of the following Spanish sports teams: soccer and basketball professional leagues, and top-division leagues for handball, volleyball, indoor soccer, and field hockey. The response rate was 81.8% (77 of 94). This survey examines (a) strength and conditioning (S&C) coach profiles, (b) resistance training exercises, (c) resistance training load, (d) repetition velocity, and (e) training leading to muscle failure. The results indicate that 80.5% of coaches held a university degree, with 22% holding a master's degrees, 40% held National Federation certification, and none held Strength and Conditioning Specialist certification. Respondents relied on nonscientific sources of information to develop their conditioning programs. Fifty-eight percent of the S&C coaches were hired full time, with 18% performing the duties of a first trainer. Many S&C coaches did not use weightlifting (54%), full squat (51%), load squat jump (35%), or bench press throw (100%) exercises. Thirty-eight percent of respondents did not control the load intensity or did not use a load of 50-90% of 1 repetition maximum. For these load intensities, 70% did not perform the combination of maximum repetition velocity and nonmuscular failure. More significant deficiencies in the fundamental principles of resistance training were observed in indoor soccer, soccer, field hockey, and among lower performing handball and basketball teams. These results indicate that the profile of the S&C coaches in the Spanish teams is insufficient for an optimal application of resistance training. Spanish S&C coaches should therefore take advantage of advances made through scientific research in the area of strength and conditioning by acquiring master's degrees and specific certificates and consulting peer-reviewer journals.