A pharmaceutical composition in an oral dosage form which comprises bendamustine or a pharmaceutically acceptable, ester, salt or solvate thereof as an active ingredient, and a pharmaceutically acceptable excipient, wherein the pharmaceutically acceptable excipient is either: - a pharmaceutically acceptable non-ionic surfactant, selected from the group consisting of a polyethoxylated castor oil, which is macrogol glycerol hydroxystearate or polyoxyl- 35- castor oil, and a block copolymer of ethylene oxide and propylene oxide which is an ethylene oxide/propylene oxide block copolymer (Pluronic ® L44 NF or Poloxamer ® 124); or - a pharmaceutically acceptable saccharide selected from the group consisting of one or more of a monosaccharide, a disaccharide, an oligosaccharide, a cyclic oligosaccharide, a polysaccharide and a saccharide alcohol, wherein the ratio by weight of the active ingredient to the saccharide excipient(s) is in the range of 1:1-5 and wherein the saccharide is selected from anhydrous dextrose, dextrose monohydrate, lactitol monohydrate, trehalose, sorbitol, erythritol, maltose monohydrate, mannitol, anhydrous lactose, lactose monohydrate, maltitol, xylitol, sucrose, sucrose 97% + maltodextrin 3%, β-cyclodextrin, D-raffinose pentahydrate, D-melezitose monohydrate and microcrystalline cellulose; which composition shows a dissolution of the bendamustine of at least 60% in 20 minutes, 70% in 40 minutes and 80% in 60 minutes, as measured with a paddle apparatus at 50 rpm according to the European Pharmacopoeia in 500 ml of a dissolution medium at a pH of 1.5, which composition is for use for the oral treatment of a medical condition which is selected from chronic lymphocytic leukemia, acute lymphocytic leukaemia, chronic myelocytic leukaemia, acute myelocytic leukaemia, Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma, breast cancer, ovarian cancer, small cell lung cancer and non-small cell lung cancer; characterised in that the active ingredient is administered orally in a cumulative dose of 350 mg to 1000 mg per patient per therapeutic cycle, wherein bendamustine and optional additional agents are dosed for 1 to 5 days and then the treatment is repeated after an interruption of 2 to 4 weeks. - a pharmaceutically acceptable non-ionic surfactant, selected from the group consisting of a polyethoxylated castor oil, which is macrogol glycerol hydroxystearate or polyoxyl- 35- castor oil, and a block copolymer of ethylene oxide and propylene oxide which is an ethylene oxide/propylene oxide block copolymer (Pluronic ® L44 NF or Poloxamer ® 124); or - a pharmaceutically acceptable saccharide selected from the group consisting of one or more of a monosaccharide, a disaccharide, an oligosaccharide, a cyclic oligosaccharide, a polysaccharide and a saccharide alcohol, wherein the ratio by weight of the active ingredient to the saccharide excipient(s) is in the range of 1:1-5 and wherein the saccharide is selected from anhydrous dextrose, dextrose monohydrate, lactitol monohydrate, trehalose, sorbitol, erythritol, maltose monohydrate, mannitol, anhydrous lactose, lactose monohydrate, maltitol, xylitol, sucrose, sucrose 97% + maltodextrin 3%, β-cyclodextrin, D-raffinose pentahydrate, D-melezitose monohydrate and microcrystalline cellulose; which composition is for use for the oral treatment of a medical condition which is selected from chronic lymphocytic leukemia, acute lymphocytic leukaemia, chronic myelocytic leukaemia, acute myelocytic leukaemia, Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma, breast cancer, ovarian cancer, small cell lung cancer and non-small cell lung cancer; characterised in that the active ingredient is administered orally in a cumulative dose of 350 mg to 1000 mg per patient per therapeutic cycle, wherein bendamustine and optional additional agents are dosed for 1 to 5 days and then the treatment is repeated after an interruption of 2 to 4 weeks.