Ongoing urbanization has led to a significant increase in the number of pets and has altered the relationships between pets and owners from primarily utilitarian to cultural (e.g., entertainment and health improvement). Existing classifications of ecosystem services (ES) (e.g., CICES) and nature’s contributions to people (NCP) explicitly consider only the ES provided by livestock and wild animals. This study attempted to translate perceived benefits and costs from owning pets (dogs or cats) in a megapolis into ES and disservices frameworks. The data were collected via an online questionnaire distributed through social media among residents of Moscow (Russia). The study showed that pets contribute to the well-being of city dwellers, for which owners are willing to put up with some potential risks and also bear monetary costs. Reasons for owning a pet have been translated into ES and NCPs ranging from regulating (4%) to provisioning (1%). However, cultural services linked to mental (26%) and physical (32%) health, spiritual, symbolic interaction (19%), and educational values (16%) have been the most prominent group. Considering an increase in pet owners, the interests and needs of this distinct stakeholder group need to be taken into account in urban planning and management. Pets’ integration into classifications and thus assessments of the urban ES can be a crucial step towards achieving this goal. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.