The present invention discloses a process for the synthesis of 3-methyl-pyridine from formaldehyde, paracetaldehyde, ammonia and acetic acid, whereby said compounds are reacted and said process comprises the following parameters: a) a reaction temperature of 260-300° C.; b) a molar ratio of formaldehyde and paraldehyde (calculated as acetaldehyde) of 0.7-1.4 mol/mol: c) an ammonia concentration of 10-20 weight-% d) an acetic acid concentration of 4-20 weight-% e) a paraldehyde (calculated as acetaldehyde) concentration of 0.4-1.6 Mol/kg f) a retention time of 10-30 minutes in case of a continuous reaction and 10-90 minutes in case of a discontinuous reaction; and g) a reaction pressure of 30-130 bar.