The toxicological effect of the aqueous extract of fresh, dried and boiled berries of Solanum aculeastrum Dunal at 1, 10 and 25 mg/kg body weight was investigated in male Wistar rats for 28 days. The parameters used were the body weight of the animals and absolute weights of the organs, haematological parameters, renal and liver functional endpoints. The animals gained appreciable weight and showed no signs of clinical toxicity. The dried (DB), boiled dried (BDB), fresh (FB) and boiled fresh berry (BFB) extracts reduced (p < .05) the heart-, liver-and spleen-body weight ratio of the animals whereas that of the lung was not altered. The kidney and testes-body weight ratios were specifically altered by the different extract. All these were not accompanied by any histomorphological changes. The extracts did not alter (p>> .05) the levels of RBC, Hb, PCV and albumin of the animals. The platelets were decreased by the DB and FB whereas BFB increased this parameter. The FB and BFB at all the doses also reduced the mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) of the animals. With the exception of the FB where the creatinine and chloride levels decreased, other extracts did not alter the level of these kidney parameters. Only FB increased the levels of uric acid and urea. All the extract decreased the serum alanine aminotransferase (ALT) of the animal. The levels of total protein, globulin, total and conjugated bilirubin were not altered by DB and BDB whereas these indices were increased by FB and BFB. The DB and BDB increased the serum alkaline phosphatase (ALP) activity whereas FB decreased the activity of the enzyme. In contrast, DB and BDB decreased the serum aspartate aminotransferase (AST) activity of the animals whereas FB and BFB increased the activity of the enzyme. The FB and BFB also increased the levels of potassium, magnesium and phosphorus of the animals. Overall, the alterations in the biochemical parameters by the various extracts of S. aculeastrum berries at these doses indicated that the normal functioning of these organs may be adversely affected. However, drying and boiling might reduce the toxic effect of the berries.