Background : Smartphone use during postural-locomotor tasks is an everyday activity for individuals of all ages in diverse environmental situations and with various health conditions. Nevertheless, the use of smartphones during walking is responsible for many accidents. Research question : This systematic review and meta-analysis examined spatiotemporal gait parameters during the dual-task situation “texting + gait” versus isolated gait task (single task) in adult persons (>18 years). Methods : Electronic database searches were performed in PubMed, Embase, CINHAL, and LISSA. Two examiners assessed the eligibility and quality of appraisal with the Downs and Black checklist. The standardized mean difference (SMD) with 95 % confidence intervals was calculated to compare single- and dual-task situations. The pooled estimates of the overall effect were computed using a random or fixed effects method, and forest plots were generated. Results and significance : A total of 25 studies were included. All studies included healthy adults, with four studies including older persons and three including people with pathological conditions. The walking task was with (N = 4) and without (N = 21) obstacles and in laboratory (N = 21) or ecological conditions (N = 7). The quality scores were 6–8/16 for eight studies, 9–12/16 for seven studies, and more than 12/16 for three studies. During the “texting + gait” tasks, the meta-analysis highlighted a significant impairment of gait speed, step and stride length, cadence, and double and single support (p < 0.05). The spatiotemporal parameters of gait were systematically altered during the texting task regardless of the population and test conditions. However, the quality of the studies is moderate, and few studies have been conducted for people with motor deficiencies. The impact of texting on walking should be better considered to develop prevention actions.