kafa'ah, an Islamic concept, signifies similarity or compatibility, often regarded as a guiding principle for selecting a prospective spouse. Although, the selection of a husband or wife based on kafa'ah is a common condition, past studies have shown that there are negative implications if the selection of the prospective husband or wife denies the guidance of kafa'ah. This article analyzes the impact of marriage without kafa'ah on a harmonious interpersonal relationship within the family according to the perspective of informants who were legal practitioners, Islamic family law academics, and family counselors. This study utilized a qualitative research methodology and semi-structured interview approach involving eight (8) informants  who were legal practitioners, Islamic family law academics, and family counselors. Data was analyzed using Atlas.ti version 8 software in open coding and presented in narrative form. The findings indicated that Islamic law indirectly influenced spouse selection in Malaysia, particularly through the prohibition of marrying non-Muslims based on kafa'ah considerations. Participants emphasized that marriages without kafa'ah could lead to domestic conflicts, yet acceptance of differences and effective communication could bridge the gap between spouses. kafa'ah, a subjective concept, evolved with lifestyle and socioeconomic changes, underscoring the need to develop criteria for building prosperous families and educating communities.