Desmond Henry was accused of putting residents of the Watermarque development, on Browning Street, at risk by spending too much time viewing a dirty website, at Birmingham Employment Tribunal.
Mr Henry, of Marshall Street, Smethwick claimed he was unfairly dismissed by his employers. Mainstay Facilities Management Ltd.
He had worked for the firm for eight years and he was sacked for gross misconduct.
He claimed he was viewing the images for educational purposes and that he was studying the human anatomy.
But the tribunal rejected his allegations and his claims for unfair dismissal.
Daniel Potter, a management official for the firm, told the tribunal that the firm received a complaint that Mr Henry was spending too much time on a pornography website at his office at the block.
He said the complainant reported that Mr Henry was not carrying out his security duties to the full.