The study emphasizes the value of gender equality and diversity in workplaces, highlighting the unique talents and skills both genders bring. Despite evidence showing that gender stereotypes can influence HR managers' recruitment decisions, leading to biases, gender diversity programs remain beneficial. Implicit biases, often unconscious, are more common than explicit ones, with women frequently being disadvantaged. While extensive research exists globally, few studies have examined gender discrimination within the Nigerian context. This study focuses on recruitment as part of the job promotion process in four Nigerian organizations, using secondary research to identify evidence of implicit gender bias in hiring practices. The findings reveal significant gender gaps in entry-level and senior management roles, attributed to factors such as gender-specific CV requirements, biased performance evaluation tools, insufficiently trained evaluators, and entrenched societal patriarchy. The study concludes that unconscious gender bias persists in Nigeria, disadvantaging women. To address this, it recommends measures such as implementing anonymous recruitment to conceal gender-sensitive identifiers, revising patriarchal societal norms, developing standardized performance evaluation criteria, and providing regular training for performance assessors to reduce bias during recruitment.