Lymph node metastasis of lung cancer is an important factor for deciding on surgical indications. Radiological pure-solid lung cancer is a highly aggressive feature, even in small lesions, and it is generally difficult to evaluate lymph node metastasis based on preoperative clinical examinations. We focused on the radiological association between the tumor and pleura and assessed the influence of pleura-tumor proximity on the risk of lymph node metastasis and postoperative recurrence. We retrospectively reviewed a consecutive series of 133 patients with clinical stage I lung cancer possessing pure-solid nodule on chest computed tomography who had undergone lobectomy with systematic lymph node dissection between January 2009 and December 2016. Figure shows the definition of positive pleura-tumor proximity. A multiple logistic regression analysis was used to identify the predictors for lymph node metastasis, and a multiple Cox proportional hazards model was used to identify the predictors for postoperative recurrence, with covariates of age, gender, performance status, resected side, pulmonary function, tumor size, pleural tag, pleura-tumor proximity, and maximum standardized uptake on positron emission tomography. There were 89 men (mean age 70.7 ± 9.6 years). The mean tumor size was 22.9 ± 8.7 mm. Lymph node metastasis was found in 21 patients (15.7%), and postoperative recurrence was found in 24 patients (18%). According to the multivariate analysis, the age (p = 0.013) and positive pleura-tumor proximity (p = 0.036) were the independent predictive factors of lymph node metastasis, and the positive pleura-tumor proximity (p = 0.035) was an independent predictive factor of postoperative recurrence. Pleura-tumor proximity in radiological pure-solid lung cancer was associated with lymph node metastasis and postoperative recurrence. Such pleura-tumor proximity should therefore be taken into consideration in the therapeutic decision-making for stage I lung cancer possessing pure-solid nodules.