A police statement said that the siblings, who are aged five, ten and 11, ventured out onto the street to seek help.
They approached a council gardener working near their home and said that they hadn't eaten for days and had been “unable to wake” their mother, who was lying in bed.
Authorities suspect that the woman, aged 40, died of ‘natural causes' in her sleep up to four days ago but are awaiting the results of a post mortem.
The woman has been identified as a Nigerian national and all three of children were born in Spain.
The children are now being cared for by social services, while authorities attempt to trace relatives. They have been treated at Palma's Son Espases Hospital.