Background: Seasonal allergic rhinitis (SAR), also known as hay fever, is a widespread chronic respiratory disease. In treatment of SAR the use of complementary therapies is increasing, but little has been published about homeopathic complex remedies so far. Therefore, we think it is time to conduct and publish an appropriate observational study. Methods: Course of single symptoms, impairment of quality of life, general efficacy, and tolerability of a homeopathic complex remedy containing active substances on a low dilution level have been assessed and analyzed. Altogether, 123 patients with a history of allergic rhinitis of up to 45 years have been observed for about 4 weeks. Results: The majority of symptoms were shown to improve substantially and the patients' quality of life increased clearly. The overall symptom score decreased significantly from 10.3 ± 4.7 to 3.9 ± 3.1 points (p < 0.0001), and reduction of impairment of quality of life from 5.7 ± 2.3 to 1.9 ± 1.8 score points was also significant (p < 0.0001). Rating of efficacy of study medication was markedly better than efficacy rating of previous therapies (p = 0.0193). Apart from one temporary allergic reaction, the treatment was well tolerated. Conclusion: The homeopathic complex remedy (Pascallerg®) tested in this observational study offers a useful option in treatment of SAR in children and adults.