Background/Objective: Patent Medicine Vendors (PMVs) are the first line of care for most suspected tuberculosis patients in resource-limited settings, given their proximity and familiarity with the community. This study was conducted among PMVs to evaluate their knowledge, attitudes, and preventive practices (KAP) regarding tuberculosis patients, with the aim of enhancing tuberculosis care in Nigeria. Methods This study used a validated structured questionnaire, adapted from the WHO-KAP study guide, to elicit responses from PMVs. The data generated were analysed using the SPSS statistical package. Results A total of 349 PMVs participated in the study, comprising 104 (29.8%) males and 245 (70.2%) females. Most respondents were 21–30 years old (134/38.4%) and had never been trained for tuberculosis infection prevention and control (207/59.3%). A good number of the respondents had adequate knowledge (196/56.2%), good attitude (199/57%) and good preventive practices (279/79.9%). However, we obtained the following KAP scores: an overall adequate knowledge score of 56.1%, an overall good attitude score of 66.9%, and an overall good preventive practices score of 79.5%. The differences between the two study sites regarding knowledge (P = 0.012), attitude (P < 0.001), and preventive practices (P = 0.039) were statistically significant. Location, gender, age, education, work experience, tuberculosis training, and the frequency of seeing tuberculosis patients were the predictors of good KAP scores. Conclusions The existence of KAP gaps among the informal health sector, represented by PMVs, has negative implications for tuberculosis prevention and control. However, these gaps reinforced the need for a more robust, focused awareness campaign to enhance tuberculosis care.