The study examined succession planning strategies and sustainability of family owned business in Southeast Nigeria. Specifically, the study sought to: determine the impact of mentoring succession strategy on continuity of Family Owned Businesses (FOBs) and examine the impact of external coaching succession strategy on survival of Family Owned Businesses (FOBs). The research design was descriptive survey method. Study Area was South East, Nigeria. The sample size of 388 respondents was drawn from 13,455 staff of 45 family owned businesses (FOB) in South-East Nigeria. Research questions of the study were answered using mean score and standard deviation. The hypotheses stated were tested using single regression statistics. The empirical results showed that mentoring succession strategy has significant impact on continuity of Family Owned Businesses (FOBs) in South East, Nigeria (t-statistic; 6.445; P-value; 0.000 < Sig-value; 0.05) and external coaching succession strategy has significant impact on survival of Family Owned Businesses (FOBs) in South East, Nigeria (t-statistic; 11.226; P-value; 0.000 < Sig-value; 0.05). The study recommended that founders of Family owned businesses in South-east Nigeria should embark on adequate application of strategic planning in the management succession of Family Owned Businesses (FOB) by developing and focusing on long range objectives and short term priorities through the adoption of mentoring program, talent retention strategies, executive coaching and external consultancy coaching.