Objective This study aims to analyze the incidence and mortality of lung cancer in Shanghai from 2002 to 2019 and their variation trends. Methods Data on lung cancer incidence and mortality in Shanghai from 2002 to 2019 were obtained from the population-based cancer registry management system and all-cause mortality registration system established by the Shanghai Municipal Center for Disease Control and Prevention. Stratified analyses were conducted by factors including year of diagnosis or death, sex, and age group, and indicators such as number of cases, constituent ratio, crude rate, age-specific rate, and age-standardized rate (ASR) were calculated. ASRs were calculated using Segi's 1960 world standard population. Joinpoint software was used to analyze annual percentage variation trends in ASRs, age-specific rates, and the constituent ratios of selected diagnostic characteristics of new cases across different groups. Results Annual new lung cancer cases in Shanghai increased from 8 005 in 2002 to 21 835 in 2019, and the age-standardized incidence rate increased from 33.73/10⁵ to 63.82/10⁵. Annual deaths increased from 6 871 to 9 573, while the age-standardized mortality rate decreased from 27.90/10⁵ to 21.75/10⁵. In 2019, the age-standardized incidence rate of lung cancer in Shanghai was 63.82/10⁵, including 66.37/10⁵ in males and 62.09/10⁵ in females, and the sex difference was statistically significant (P<0.001). The age-standardized mortality rate was 21.75/10⁵, with 33.50/10⁵ in males and 10.95/10⁵ in females, and the sex difference was statistically significant (P<0.001). Age-specific numbers and rates of lung cancer incidence and mortality generally increased with age. Sex-stratified trend analysis showed that from 2002 to 2019, the age-standardized incidence rate of lung cancer in males in Shanghai increased at an average annual rate of 1.39% (P=0.006), while the age-standardized mortality rate decreased at an average annual rate of 0.98% (P<0.001). In females, the age-standardized incidence rate showed no significant change from 2002 to 2011 (P=0.717), but increased at an average annual rate of 15.57% from 2011 to 2019 (P<0.001). The age-standardized mortality rate showed no statistically significant change from 2002 to 2012 (P=0.779), but decreased at an average annual rate of 2.95% from 2012 to 2019 (P=0.011). Among newly diagnosed lung cancer cases in Shanghai from 2002 to 2019, the proportion confirmed by pathology increased from 44.28% to 61.88%, while the proportion confirmed by imaging examination decreased from 41.50% to 7.99%. The proportion of adenocarcinoma increased from 19.66% to 41.20%, while that of squamous-cell carcinoma decreased from 14.13% to 6.29%. The proportion of stage Ⅰ patients increased from 3.76% to 22.60%, whereas the combined proportion of stage Ⅱ to stage Ⅳ patients decreased. However, the proportions of cases with unspecified anatomic site, unspecified histological type, and unknown stage at diagnosis remained high, and in 2019, the proportions were 75.65%, 45.89%, and 54.05%, respectively. Conclusions In 2019, compared with the global level, the age-standardized incidence rate of lung cancer in Shanghai, China, was relatively high, and mortality showed distinct epidemiological characteristics across sex and age groups. The incidence rate of lung cancer in females showed an overall upward trend from 2002 to 2019. In 2019, the age-standardized incidence rate of lung cancer in females increased with age. These findings suggest that there is still substantial room for improvement in lung cancer screening, diagnosis, and survival. This study provides a basis for further research and prevention and control strategies for lung cancer.