Anxiety, depressive symptoms and stress have a significant influence on chronic musculoskeletal pain. Behavioral modification techniques have proven to be effective to manage these variables; however, the COVID-19 pandemic has highlighted the need for an alternative to face-to-face treatment. We conducted a search of PubMed, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, APA PsychInfo, and Psychological and Behavioural Collections. The aim was to assess the effectiveness of telematic behavioral modification techniques (e-BMT) on psychological variables in patients with chronic musculoskeletal pain through a systematic review with meta-analysis. We used a conventional pairwise meta-analysis and a random-effects model. We calculated the standardized mean difference (SMD) with the corresponding 95% confidence interval (CI). Forty-one randomized controlled trials were included, with a total of 5018 participants. We found a statistically significant small effect size in favor of e-BMT in depressive symptoms (n = 3531; SMD = -0.35; 95% CI -0.46, -0.24) and anxiety (n = 2578; SMD = -0.32; 95% CI -0.42, -0.21) with low to moderate strength of evidence. However, there was no statistically significant effect on stress symptoms with moderate strength of evidence. In conclusion, e-BMT is an effective option for the management of anxiety and depressive symptoms in patients with chronic musculoskeletal pain. However, it does not seem effective to improve stress symptoms.