Background: Human immunodeficiency virus (HIV) remains a major concern globally and locally. Married couples and those in stable relationships account for the highest percentage of new HIV and acquired immune deficiency syndrome (AIDS) infections. The rate of HIV disclosure among couples is low and affected by both known and unknown factors. The aim of this study was to describe the reasons for HIV status (non)disclosure among partners in Morongo. Methods: A sampling containing two stages was used in this quantitative, exploratory, and descriptive study to select the 100 participants. The location was a Care and Treatment Clinic in the Morogoro municipality. Results: The participants had a moderate level of knowledge about the importance of HIV serostatus disclosure. Female genital mutilation was the most mentioned (44%) custom affecting disclosure. The participants’ level of knowledge about their partner's HIV status was also moderate (28%). Nitty-six percent had not disclosed due to fear of divorce and 98% due to fear of loss of financial support. Cultural factors such as traditional practices (95%) were also a major reason that hindered disclosure. Conclusions: Interventions to address the negative attitudes are necessary to promote HIV disclosure and, in turn, better adherence to psychological adjustment therapy and reduction in the risk of HIV transmission among couples.