Mathematics, being the core subject that has its application in every other subject should be given special attention. Despite the importance of mathematics, students are not performing in the subject. Students view mathematics in abstract form. Ways of improving the teaching and learning of mathematics should be the concern of the stakeholders. A lot of research work were reported on teaching strategies, but the problem of poor performance has not been reduced to minimal level. Students thinking and error made in class can be used to create teachable moments. This study investigated whether the teachers of mathematics in Nigeria are aware, managing and using teachable moments when occur in mathematics class. The study is a descriptive research of the survey type. The sample consisted of 98 mathematics teachers randomly selected from thirty secondary schools from both Lagos and Oyo states of Nigeria. A researcher-designed of effective management of Teachable Moments which consists of 3 parts was used to collect data from the respondents. The first section of the questionnaire was used to elicit general information on teachers’ demographical data. The 3 parts of the second section include awareness of teachable moment (ATM), Management of Teachable Moment with resources (MTM) and Use of Teachable Moments (UTM). All instruments were validated. The reliability coefficient of ATM, MTM and UTM using Cronbach alpha were 0.72, 0.78 and 0.69 respectively. Means and standard deviation were used to analyze the data. It was discovered that the means of the awareness and management instruments were greater than the baseline mean (2.5). Teachers are aware, can manage but are not using the moments due to time constraint. This indicated that mathematics teachers in Nigeria are aware of teachable moments, managing the moments effectively but have not been using teachable moments.