Introduction: We designed a test to evaluate useful force in tennis forehand using atlas ergodynamometry. Objective: To evaluate useful force in tennis players. Method: Eight tennis players (6 men and 2 women) performed 10 consecutive forehands (with prior warm-up). Results: The mean acceleration time was 0.20 ± 0.01 seconds, the maximum force was 63.79 ± 9.79, the ascending hypotenuse was 67.45 ± 9.02 Newton/second (N/sec), the alpha angle was 70.04 ± 4.04°, the beta angle beta was 19.88 ± 4.07°, and explosive force was 304.08 ± 57.66 N/sec. Differences were observed by sex: acceleration time was 0.20 ± 0.008 seconds in men compared with 0.22 ± 0.02 seconds in women. The mean maximum force was 68.23 ± 6.06 N in men and 50.38 ± 2.80 N in women. The ascending hypotenuse was 72.22 ± 6.10 N/sec in men and 55.32 ± 3.57 N/sec in women. The alpha angle was 71.63 ± 3.28° in men and 65.28 ± 0.50° in women. The beta angle was 18.27 ± 3.27° in men and 24.71 ± 0.50° in women. Explosive force in men oscillated between 356 and 280 N/sec, with a mean value of 331.1 ± 33.91 N/sec while that in women oscillated between 227.1 and 219 N/sec, with a mean value of 223.1 ± 5.65 N/sec. Conclusion: The atlas ergodynamometry test is useful for evaluating force in tennis players.