The role of a family history of lung cancer (LCFH) in screening using low-dose computed tomography (LDCT) has not been prospectively investigated with long-term follow-up. A multicenter prospective study with up to three rounds of annual LDCT screening was conducted to determine the detection rate of lung cancer (LC) in asymptomatic first- or second-degree relatives of LCFH. From 2007 to 2011, there were 1102 participants enrolled, including 805 and 297 from simplex and multiplex families (MFs), respectively (54.2% women and 70.0% never-smokers). The last follow-up date was May 5, 2021. The overall LC detection rate was 4.5% (50 of 1102). The detection rate in MF was 9.4% (19 of 202) and 4.4% (4 of 91) in never-smokers and in those who smoked, respectively. The corresponding rates for simplex families were 3.7% (21 of 569) and 2.7% (6 of 223), respectively. Of these, 68.0% and 22.0% of cases with stage I and IV diseases, respectively. LC diagnoses within a 3-year interval from the initial screening tend to be younger, have a higher detection rate, and have stage I disease; thereafter, more stage III–IV disease and 66.7% (16 of 24) with negative or semipositive nodules in initial computed tomography scans. Within the 6-year interval, only maternal (modified rate ratio = 4.46, 95% confidence interval: 2.32–8.56) or maternal relative history of LC (modified rate ratio = 5.41, 95% confidence interval: 2.84–10.30) increased the risk of LC. LCFH is a risk factor for LC and is increased with MF history, among never-smokers, younger adults, and those with maternal relatives with LC. Randomized controlled trials are needed to confirm the mortality benefit of LDCT screening in those with LCFH.