Background <p>Adolescent Internet addiction has emerged as a major social and public health concern worldwide. Previous studies have indicated that parent–child relationship plays a crucial role in adolescent Internet addiction. However, most of these studies have adopted a cross-sectional design, making it difficult to reveal the lagged effects of the parent-child relationship on adolescent Internet addiction and its underlying developmental mechanisms.</p> Methods <p>This study conducted a three-wave survey over one year, employing cluster sampling between October 2023 and October 2024. The survey assessed parent-child relationship, Internet addiction, basic psychological need frustration, and self-esteem among 2,483 adolescents (<i>M</i>_age = 13.82, <i>SD</i> = 1.53; 51.71% girls) from two middle schools in Shaanxi, China. Descriptive statistics and correlation analyses were performed using SPSS 26.0. Additionally, the lagged effect of T1 parent-child relationship on T3 Internet addiction, as well as the parallel mediating roles of T2 basic psychological needs frustration and T2 self-esteem in this lagged effect, were examined using PROCESS macro Model 4.</p> Results <p>(1) The lagged effect of T1 parent-child relationship on T3 Internet addiction was significant (<i>β</i> = −0.20, <i>SE</i> = 0.03, <i>p</i> &lt; 0.001). (2) T2 basic psychological need frustration (<i>β</i> = −0.06, <i>SE</i> = 0.01, 95% CI: −0.08, − 0.04) and T2 self-esteem (<i>β</i> = −0.02, <i>SE</i> = 0.01, 95% CI: −0.04, − 0.01) served as parallel mediators in the lagged effect of T1 parent-child relationship on T3 Internet addiction.</p> Conclusions <p>These findings provide empirical evidence for preventing and intervening in adolescent Internet addiction and hold significant implications for reducing its risk.</p>