Introduction: Available endobronchial valves (EBVs) for lung volume reduction in severe emphysema are limited in variety and predominantly feature complex metal-silicone designs (e.g., Zephyr®). This study aimed to introduce a novel, all-silicone endobronchial valve (ESV) designed to simplify manufacturing and potentially improve biocompatibility. Methods: A preclinical study implanted ESVs or Zephyr® EBVs (1:1) into unilateral caudal lobes of 8 pigs, assessed using computed tomography, bronchoscopy, and necropsy over 6 weeks. A first-in-human (FIH) trial enrolled 3 severe emphysema patients (male, aged 48–72 years, collateral ventilation-negative). ESVs were placed using a bronchoscope under general anaesthesia. Outcomes included procedural success, safety, target lobar volume reduction, lung function, quality of life, and exercise capacity at baseline and 3 and 6 months. Results: Preclinically, all valves (12 ESV, 12 Zephyr®) were successfully implanted and removed. Complete target lobe atelectasis occurred by 6 weeks in all animals, without major adverse events; localised granulation was observed. In the FIH trial, all ESVs were successfully deployed (procedure time: 5–20 min). Target lobar volume reductions occurred at 6 months in 2 of 3 cases (Case 1: 1.5 L, Case 2: 0.4 L). Emphysema volume decreased at 3 and 6 months. Lung function, quality of life, and exercise capacity showed trends toward improvement. One patient experienced an acute exacerbation of chronic obstructive pulmonary disease; no pneumothorax, pneumonia, or haemoptysis occurred. Conclusion: Overall, ESV was shown to have an initial feasibility for endobronchial lung volume reduction in humans. Further studies are needed to evaluate the sustained effects.