The welfare of pet rabbits is frequently compromised despite increasing recognition of their complex behavioural and physiological needs. Although owner knowledge is considered an important determinant of animal care, the relationship between perceived knowledge and actual husbandry practices remains poorly understood. This study aimed to (i) describe husbandry practices and owner-reported knowledge among pet rabbit owners in Croatia and (ii) assess whether higher perceived knowledge is associated with greater alignment with recommended husbandry practices. Data were collected using an online questionnaire distributed to rabbit owners (n = 529). The study assessed owner-reported husbandry practices and perceived knowledge but did not include direct assessments of rabbit health or welfare. Although most respondents reported high levels of knowledge regarding rabbit care (85.6%), this was not consistently reflected in implemented husbandry practices. Higher perceived knowledge was significantly associated (p < 0.05) with environmental enrichment, housing type, and cleaning frequency, but these associations were generally weak to moderate. In contrast, perceived knowledge showed little or no association with several key welfare-related practices, including social housing and access to free movement, while only limited associations were observed for feeding practices. These findings reveal a substantial knowledge–practice gap, suggesting that confidence in rabbit care knowledge does not necessarily translate into appropriate husbandry. Therefore, educational approaches focused solely on information provision may be insufficient to ensure the implementation of recommended husbandry practices.