This quantitative double-blind, pretestposttest experimental pilot study examined two research questions in a sample of adults diagnosed with ADHD in the Niagara Region of Ontario, Canada. The questions asked, if and to what extent cranial electrotherapy stimulation (CES) increases attention (measured using the IVA-FSAQ) and sleep quality measured using the PSQI. The biopsychosocial model provided the framework for this study. Fifteen participants were randomly assigned to sham or active treatment conditions and used CES for 60 min each day for 5 weeks. A mixed between-within-subjects MANOVA demonstrated a significant multivariate main effect of time F(2, 12) = 7.09, p =.009; Wilks’ Λ = .458; and partial η² = .542. Both groups showed improvement in attention and sleep quality at posttest. Follow-up univariate analysis revealed that the time effect was statistically significant for both attention F(1, 13) = 5.30, p = .038; partial η² = .29 and sleep quality F(1, 13) = 15.33, p = .002; partial η² = .541. There was no statistically significant multivariate effect of the treatment (sham vs. active CES) or for the interaction between time and treatment group. Effect sizes were large, and it is likely that a larger sample size would have revealed conclusive results regarding the interaction between time and treatment group. Qualitative data showed that sham participants had engaged in extraneous activities that could improve sleep during participation. Results support the use of CES as an adjunctive sleep aid in adults suffering from ADHD.