This study examined the impact of mandatory information disclosure on compliance with companies and allied matter Act(CAMA) of telecommunication companies in Nigeria. The study adopted ex-post facto research design which relied on secondary data collected from the financial statements of three (3) telecommunication companies for the period of 2004 to 2015. The multiple regression model was used to analyze the data. The results indicated that computed compliance index of telecommunication companies were partially complied (av.75.6%) with the requirements of regulatory agencies. Furthermore, the finding revealed that accounting policies has significant impact at 1%, this shows positive compliance by the telecommunication companies, balance sheet and profit and loss has significant impact at 5%. This means that there is a partial compliance by the telecommunication companies, the auditor’s report has significant impact at 10%, and this shows weak compliance by the telecommunication companies. While directors report is insignificant. This means that there is non- compliance by the telecommunication companies. It is concluded that the level of compliance with existing regulation required was partial which showed some internal weaknesses and consequent distress in the operations of the telecommunication companies in Nigeria. To this effect, there is a clarion call for the enforcement of full compliance by all the Telecommunication companies in Nigeria. It is therefore recommended that National Communication Commission should monitor the compliance with the requirements of mandatory information disclosure and pursue its objective to achieve best corporate governance practices in Nigerian telecommunication companies.