This article reports preliminary evidence for the effectiveness of eye movement desensitization and reprocessing psychotherapy (EMDR) therapy, applying bilateral alternating tactile stimulation in treating cognitive symptoms in patients with generalized anxiety disorder (GAD). A single-case experimental design was used in seven clinical cases. The Penn State Worry Questionnaire, Intolerance of Uncertainty, Cognitive Avoidance Questionnaire, and Negative Problem Orientation Questionnaire were administered at five points during pretreatment (which established the baseline phase serving as each participant's control), at three points during the treatment phase, at the end of it, and at the 3- and 6-month follow-ups. Each participant received 16 treatment sessions. Visual, statistical, and clinical significance analyses were conducted. The cognitive symptoms treated were: excessive worry, intolerance of uncertainty, cognitive avoidance, and negative orientation to problems. All four cognitive symptoms subsided, with large effect sizes in all cases, between pre- and posttreatment, which can be observed in the visual and statistical analysis of each case. Pre- and post-cognitions are specified in each case. According to the clinical significance analysis, all participants evidenced a change towards an improvement. Finally, evidence is given in favor of the usefulness of EMDR therapy for the treatment of cognitive symptoms in participants diagnosed with GAD. However, these results must be considered cautiously when generalizing data.