A tubular lighting device comprising an elongated heat sink (3), at least one light source (5) mounted on the elongated heat sink (3), and an elongated hollow tubular member (7) with a first and a second end arranged along the elongated heat sink (3). The tubular member (7) comprises a lens (15) and a light exit surface (9). The light exit surface is located in front of the lens (15) and the light exit surface (9) have at least one diffusing portion (11) with a transparent portion on each side of each diffusing portion. The at least one diffusing portion (11) covers an area on the light exit surface (9) corresponding to a light distribution of said lens (15) projected on the light exit surface (9), such that all light is directed by said lens (15) onto the at least one diffusing portion (11).