The bar association said the planned strike was to register its discontent for posterity.
It also urged aggrieved candidates to make full use of election tribunals to seek redress.
April's elections for a new president, state governors and legislators were billed as the first fully democratic transition in Nigeria, Africa's most populous country and leading oil producer.
European observers instead reported that widespread fraud occured during the polls, which gave a landslide victory to the ruling party, and said the results were "not credible".
Opposition parties have called for a re-run but the constitution does not allow a second election to be held.
The lawyers' call follows an announcement by the Nigeria Labour Congress, an umbrella body of workers' unions, that it would also organise a two-day strike before May 29, when president-elect Umaru Yar'Adua is due to take office.