Arabic-speaking immigrants and refugees constitute one of the largest immigrant groups in Sweden. Previous research on Arabic-speaking immigrants indicates elevated levels of psychological disorders, including depression and anxiety. The aim of the present pilot study was to examine the efficacy of an internet-delivered cognitive behavioural treatment (ICBT) in an Arabic-speaking immigrant population. The intervention was individually tailored based on self-described problems and consisted of nine modules targeting areas such as depression, anxiety and insomnia. In total, 59 individuals were included and randomized to either an 8-week treatment or wait-list control. Self-reported symptoms of depression on the PHQ-9 were used as primary outcome measure. Secondary outcome measures of anxiety, stress, insomnia, quality of life and post-traumatic stress were also used. In the intention-to-treat analysis, depressive symptoms were significantly reduced compared to the wait-list control group with a between-group effect at post-treatment of Cohen’s = 0.85 [0.29, 1.41]. We also found significant between-group effects for symptoms of insomnia and stress, but not for anxiety, post-traumatic stress or quality of life measures. The results indicate that ICBT is a promising treatment approach for treating symptoms of depression, insomnia and stress, in an Arabic-speaking immigrant population. Further studies with larger samples are warranted.