Spruce (Picea species), especially in the form of essential oil or inhaled preparations, has traditionally been used in folk medicine for respiratory complaints, including sinus congestion. Indigenous peoples and early herbalists often utilized spruce needles, resins, or oils as part of steam inhalations or balms, believing that the aromatic compounds could help clear nasal passages and ease breathing. The primary constituents in spruce oil—such as bornyl acetate, camphene, and alpha-pinene—are similar to those found in other coniferous essential oils traditionally used for respiratory support. However, scientific validation for spruce’s efficacy in treating sinus congestion is quite limited. While there is some evidence that inhaling volatile oils (like eucalyptus or pine) can temporarily reduce the perception of congestion by stimulating cold receptors and providing a subjective sensation of easier breathing, specific clinical research on spruce oil is lacking. The evidence level is therefore rated as 2: mainly based on traditional use, with some plausible mechanisms but minimal direct clinical data. In summary, the use of spruce for sinus congestion is primarily rooted in tradition and anecdotal practice. While the aromatic compounds in spruce may provide short-term relief through their scent and mild expectorant properties, more rigorous scientific studies are needed to confirm its effectiveness and safety for this purpose.